Particle size control of metallocene catalyst systems in loop slurry polymerization reactors

ABSTRACT

Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 μm and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. patent applicationSer. No. 17/092,394, filed on Nov. 9, 2020, now U.S. Pat. No.11,124,586, the disclosure of which is incorporated herein by referencein its entirety.

FIELD OF THE INVENTION

The present disclosure generally relates to loop slurry polymerizationprocesses for producing ethylene polymers, and more particularly,relates to the use of metallocene-based catalyst systems with particularparticle size attributes in these loop slurry polymerization processes.

BACKGROUND OF THE INVENTION

Improper particle size features of metallocene-based catalyst systemscan lead to operational difficulties during ethylene/α-olefinpolymerizations in loop slurry reactors, as well as poor andinconsistent properties of the resulting polymer. It would be beneficialto develop catalyst systems and polymerization processes that overcomethese drawbacks. Accordingly, it is to these ends that the presentinvention is generally directed.

SUMMARY OF THE INVENTION

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify required oressential features of the claimed subject matter. Nor is this summaryintended to be used to limit the scope of the claimed subject matter.

The present invention generally relates, in one aspect, tometallocene-based catalyst compositions and to slurry polymerizationprocesses using the catalyst compositions. Such catalyst compositionscan comprise a metallocene compound (one or more than one), a solidactivator, and optionally, a co-catalyst. The solid activator (or thesupported metallocene catalyst) can have a d50 average particle size ina range from 15 to 50 μm and a particle size span ((d90−d10)/d50) in arange from 0.5 to 1.5. Polymerization processes using themetallocene-based catalyst composition can comprise contacting thecatalyst composition with an olefin monomer and an optional olefincomonomer in a polymerization reactor system comprising a loop slurryreactor under polymerization conditions to produce an olefin polymer.

Ethylene polymer powder (or fluff) produced by the polymerizationprocesses can have, in another aspect, a d50 average particle size in arange from 150 to 600 μm, a particle size span in a range from 0.5 to1.6, less than or equal to 20 wt. % of the composition with a particlesize of less than 100 μm, and less than or equal to 5 wt. % of thecomposition with a particle size of greater than 1000 μm.

In yet another aspect, the present invention also is directed toethylene polymers characterized by a high load melt index (HLMI) in arange from 4 to 10 g/10 min, a density in a range from 0.944 to 0.955g/cm³, and a higher molecular weight component and a lower molecularweight component, in which the higher molecular weight component canhave a Mn in a range from 280,000 to 440,000 g/mol, and the lowermolecular weight component can have a Mw in a range from 30,000 to45,000 g/mol and a ratio of Mz/Mw in a range from 2.3 to 3.4. The lowermolecular weight component can be the majority of the ethylene polymer,typically ranging from 56 to 72 wt. % of the ethylene polymer, which istypically in the form of pellets or beads.

Both the foregoing summary and the following detailed descriptionprovide examples and are explanatory only. Accordingly, the foregoingsummary and the following detailed description should not be consideredto be restrictive. Further, features or variations may be provided inaddition to those set forth herein. For example, certain aspects andembodiments may be directed to various feature combinations andsub-combinations described in the detailed description.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 presents a plot of the particle size distributions of theInventive 1, Inventive 2, Comparative 1, and Comparative 2 solidactivators.

FIG. 2 presents a plot of the particle size distributions of theInventive 1, Inventive 2, Comparative 1, and Comparative 2 polymerpowders.

FIG. 3 presents a plot of film gel count versus time as the Comparative2 catalyst is transitioned to the Inventive 1 catalyst.

FIG. 4 presents a plot of segregation test results for the Comparative 2polymer powder.

FIG. 5 presents a plot of the flotation density distribution of theInventive 1, Inventive 2, and Comparative 2 polymer powders.

FIG. 6 presents a plot of the molecular weight distributions of thepolymers of Examples 1, 4, 12, 18, 21, and 36.

DEFINITIONS

To define more clearly the terms used herein, the following definitionsare provided. Unless otherwise indicated, the following definitions areapplicable to this disclosure. If a term is used in this disclosure butis not specifically defined herein, the definition from the IUPACCompendium of Chemical Terminology, 2nd Ed (1997), can be applied, aslong as that definition does not conflict with any other disclosure ordefinition applied herein, or render indefinite or non-enabled any claimto which that definition is applied. To the extent that any definitionor usage provided by any document incorporated herein by referenceconflicts with the definition or usage provided herein, the definitionor usage provided herein controls.

Herein, features of the subject matter are described such that, withinparticular aspects, a combination of different features can beenvisioned. For each and every aspect and/or feature disclosed herein,all combinations that do not detrimentally affect the designs,compositions, and/or methods described herein are contemplated with orwithout explicit description of the particular combination.Additionally, unless explicitly recited otherwise, any aspect and/orfeature disclosed herein can be combined to describe inventive featuresconsistent with the present disclosure.

While compositions and methods are described herein in terms of“comprising” various components or steps, the compositions and methodsalso can “consist essentially of” or “consist of” the various componentsor steps, unless stated otherwise. For example, a catalyst compositionconsistent with aspects of the present invention can comprise;alternatively, can consist essentially of; or alternatively, can consistof; catalyst component I, catalyst component II, a solid activator, anda co-catalyst.

The terms “a,” “an,” “the,” etc., are intended to include pluralalternatives, e.g., at least one, unless otherwise specified. Forinstance, the disclosure of “a co-catalyst” or “a metallocene compound”is meant to encompass one, or mixtures or combinations of more than one,co-catalyst or metallocene compound, respectively, unless otherwisespecified.

Generally, groups of elements are indicated using the numbering schemeindicated in the version of the periodic table of elements published inChemical and Engineering News, 63(5), 27, 1985. In some instances, agroup of elements can be indicated using a common name assigned to thegroup; for example, alkali metals for Group 1 elements, alkaline earthmetals for Group 2 elements, transition metals for Group 3-12 elements,and halogens or halides for Group 17 elements.

For any particular compound disclosed herein, the general structure orname presented is also intended to encompass all structural isomers,conformational isomers, and stereoisomers that can arise from aparticular set of substituents, unless indicated otherwise. Thus, ageneral reference to a compound includes all structural isomers unlessexplicitly indicated otherwise; e.g., a general reference to pentaneincludes n-pentane, 2-methyl-butane, and 2,2-dimethylpropane, while ageneral reference to a butyl group includes an n-butyl group, asec-butyl group, an iso-butyl group, and a tert-butyl group.Additionally, the reference to a general structure or name encompassesall enantiomers, diastereomers, and other optical isomers whether inenantiomeric or racemic forms, as well as mixtures of stereoisomers, asthe context permits or requires. For any particular formula or name thatis presented, any general formula or name presented also encompasses allconformational isomers, regioisomers, and stereoisomers that can arisefrom a particular set of substituents.

The term “substituted” when used to describe a group, for example, whenreferring to a substituted analog of a particular group, is intended todescribe any non-hydrogen moiety that formally replaces a hydrogen inthat group, and is intended to be non-limiting. A group or groups canalso be referred to herein as “unsubstituted” or by equivalent termssuch as “non-substituted,” which refers to the original group in which anon-hydrogen moiety does not replace a hydrogen within that group.Unless otherwise specified. “substituted” is intended to be non-limitingand include inorganic substituents or organic substituents as understoodby one of ordinary skill in the art.

The term “hydrocarbon” whenever used in this specification and claimsrefers to a compound containing only carbon and hydrogen. Otheridentifiers can be utilized to indicate the presence of particulargroups in the hydrocarbon (e.g., halogenated hydrocarbon indicates thepresence of one or more halogen atoms replacing an equivalent number ofhydrogen atoms in the hydrocarbon). The term “hydrocarbyl group” is usedherein in accordance with the definition specified by IUPAC; a univalentgroup formed by removing a hydrogen atom from a hydrocarbon (that is, agroup containing only carbon and hydrogen). Non-limiting examples ofhydrocarbyl groups include alkyl, alkenyl, aryl, and aralkyl groups,amongst other groups.

The term “polymer” is used herein generically to include olefinhomopolymers, copolymers, terpolymers, and the like, as well as alloysand blends thereof. The term “polymer” also includes impact, block,graft, random, and alternating copolymers. A copolymer is derived froman olefin monomer and one olefin comonomer, while a terpolymer isderived from an olefin monomer and two olefin comonomers. Accordingly,“polymer” encompasses copolymers and terpolymers derived from any olefinmonomer and comonomer(s) disclosed herein. Similarly, the scope of theterm “polymerization” includes homopolymerization, copolymerization, andterpolymerization. Therefore, an ethylene polymer includes ethylenehomopolymers, ethylene copolymers (e.g., ethylene/α-olefin copolymers),ethylene terpolymers, and the like, as well as blends or mixturesthereof. Thus, an ethylene polymer encompasses polymers often referredto in the art as LLDPE (linear low density polyethylene) and HDPE (highdensity polyethylene). As an example, an olefin copolymer, such as anethylene copolymer, can be derived from ethylene and a comonomer, suchas 1-butene, 1-hexene, or 1-octene. If the monomer and comonomer wereethylene and 1-hexene, respectively, the resulting polymer can becategorized an as ethylene/1-hexene copolymer. The term “polymer” alsoincludes all possible geometrical configurations, unless statedotherwise, and such configurations can include isotactic, syndiotactic,and random symmetries. Moreover, unless stated otherwise, the term“polymer” also is meant to include all molecular weight polymers, and isinclusive of lower molecular weight polymers.

The term “co-catalyst” is used generally herein to refer to compoundssuch as aluminoxane compounds, organoboron or organoborate compounds,ionizing ionic compounds, organoaluminum compounds, organozinccompounds, organomagnesium compounds, organolithium compounds, and thelike, that can constitute one component of a catalyst composition, whenused, for example, in addition to a solid activator. The term“co-catalyst” is used regardless of the actual function of the compoundor any chemical mechanism by which the compound may operate.

The term “solid activator” is used herein to indicate a solid, inorganicoxide of relatively high porosity, which can exhibit Lewis acidic orBrønsted acidic behavior, and which has been treated with anelectron-withdrawing component, typically an anion, and which iscalcined. The electron-withdrawing component is typically anelectron-withdrawing anion source compound. Thus, the solid activatorcan comprise a calcined contact product of at least one solid oxide withat least one electron-withdrawing anion source compound. Typically, thesolid activator comprises at least one acidic solid oxide compound. The“solid activator” of the present invention can be a chemically-treatedsolid oxide. The term “solid activator” is used to imply that thesecomponents are not inert, and such components should not be construed asan inert component of the catalyst composition. The term “activator,” asused herein, refers generally to a substance that is capable ofconverting a metallocene component into a catalyst that can polymerizeolefins, or converting a contact product of a metallocene component anda component that provides an activatable ligand (e.g., an alkyl, ahydride) to the metallocene, when the metallocene compound does notalready comprise such a ligand, into a catalyst that can polymerizeolefins. This term is used regardless of the actual activatingmechanism. Illustrative activators include solid activators,aluminoxanes, organoboron or organoborate compounds, ionizing ioniccompounds, and the like. Aluminoxanes, organoboron or organoboratecompounds, and ionizing ionic compounds generally are referred to asactivators if used in a catalyst composition in which a solid activatoris not present. If the catalyst composition contains a solid activator,then the aluminoxane, organoboron or organoborate, and ionizing ionicmaterials are typically referred to as co-catalysts.

The term “metallocene” as used herein describes compounds comprising atleast one η³ to η⁵-cycloalkadienyl-type moiety, wherein η³ toη⁵-cycloalkadienyl moieties include cyclopentadienyl ligands, indenylligands, fluorenyl ligands, and the like, including partially saturatedor substituted derivatives or analogs of any of these. Possiblesubstituents on these ligands can include H, therefore this inventioncomprises ligands such as tetrahydroindenyl, tetrahydrofluorenyl,octahydrofluorenyl, partially saturated indenyl, partially saturatedfluorenyl, substituted partially saturated indenyl, substitutedpartially saturated fluorenyl, and the like. In some contexts, themetallocene is referred to simply as the “catalyst,” in much the sameway the term “co-catalyst” is used herein to refer to, for example, anorganoaluminum compound.

The terms “catalyst composition.” “catalyst mixture.” “catalyst system,”and the like, do not depend upon the actual product or compositionresulting from the contact or reaction of the initial components of thedisclosed or claimed catalyst composition/mixture/system, the nature ofthe active catalytic site, or the fate of the co-catalyst, metallocenecompound, or the solid activator, after combining these components.Therefore, the terms “catalyst composition,” “catalyst mixture,”“catalyst system,” and the like, encompass the initial startingcomponents of the composition, as well as whatever product(s) may resultfrom contacting these initial starting components, and this is inclusiveof both heterogeneous and homogenous catalyst systems or compositions.The terms “catalyst composition.” “catalyst mixture,” “catalyst system,”and the like, can be used interchangeably throughout this disclosure.

The term “contact product” is used herein to describe compositionswherein the components are contacted together in any order, in anymanner, and for any length of time, unless otherwise specified. Forexample, the components can be contacted by blending or mixing. Further,contacting of any component can occur in the presence or absence of anyother component of the compositions described herein. Combiningadditional materials or components can be done by any suitable method.Further, the term “contact product” includes mixtures, blends,solutions, slurries, reaction products, and the like, or combinationsthereof. Although “contact product” can include reaction products, it isnot required for the respective components to react with one another.Similarly, the term “contacting” is used herein to refer to materialswhich can be blended, mixed, slurried, dissolved, reacted, treated, orotherwise combined in some other manner.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices, and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention.

Several types of ranges are disclosed in the present invention. When arange of any type is disclosed or claimed, the intent is to disclose orclaim individually each possible number that such a range couldreasonably encompass, including end points of the range as well as anysub-ranges and combinations of sub-ranges encompassed therein. Forexample, when a chemical moiety having a certain number of carbon atomsis disclosed or claimed, the intent is to disclose or claim individuallyevery possible number that such a range could encompass, consistent withthe disclosure herein. For example, the disclosure that a moiety is a C₁to C₁₈ hydrocarbyl group, or in alternative language, a hydrocarbylgroup having from 1 to 18 carbon atoms, as used herein, refers to amoiety that can have 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, or 18 carbon atoms, as well as any range between these twonumbers (for example, a C₁ to C₈ hydrocarbyl group), and also includingany combination of ranges between these two numbers (for example, a C₂to C₄ and a C₂ to C₁₆ hydrocarbyl group).

Similarly, another representative example follows for the ratio of Mw/Mnof an ethylene polymer consistent with aspects of this invention. By adisclosure that the ratio of Mw/Mn can be in a range from 20 to 45, theintent is to recite that the ratio of Mw/Mn can be any ratio in therange and, for example, can include any range or combination of rangesfrom 20 to 45, such as from 20 to 42, from 20 to 30, or from 35 to 45,and so forth. Likewise, all other ranges disclosed herein should beinterpreted in a manner similar to these examples.

In general, an amount, size, formulation, parameter, range, or otherquantity or characteristic is “about” or “approximate” whether or notexpressly stated to be such. Whether or not modified by the term “about”or “approximately,” the claims include equivalents to the quantities orcharacteristics.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally to single metallocene anddual metallocene catalyst systems, controlling the particle size of thesolid activator in these catalyst systems, methods for using thecatalyst systems to polymerize olefins in loop slurry reactors, thepolymer resins produced using such catalyst systems, and films and otherarticles of manufacture produced from these polymer resins.

Catalyst particle sizes that perform well in certain fluidized bed gasphase processes are not transferable to loop slurry processes, due inpart to differences in catalyst loading/feeding and in downstreampolymer transfer, as well as particle settling efficiency in a gaseousmedium versus a liquid diluent. For loop slurry processes, the benefitsof smaller catalyst particle sizes generally include lower gels, moresurface area which increases the potential for collisions and masstransfer, higher saltation velocities, greater potential reactor masssolids, longer reactor residence times, higher activities, and moreefficient purge capability. However, there are significant drawbacks tothe use of small particle sizes (fines), in particular, difficultieswith activation and transfer of the activator/catalyst into the reactor,issues of downstream powder/fluff transfer (since smaller catalystparticles generally make smaller polymer particles), and higher slurryviscosity due the greater surface area of the fine particles. Anobjective of this invention, therefore, is to target a moderate averagecatalyst particle size and with a narrow particle size distribution,such that the only a small amount of catalyst particles are fines (e.g.,less than 10 microns), while also minimizing the amount of very largecatalyst particles (e.g., greater than 50 microns), which also can beproblematic, as discussed further below.

Herein, the catalyst composition contains at least one metallocenecompound, a solid activator, and typically a co-catalyst. The solidactivator (and the supported metallocene catalyst) would have thedescribed particle size distribution. Unlike many available catalystsystems, the disclosed catalyst system does not use an inert supportlike silica, nor are MAO and other similar activators needed in thecatalyst system.

While not wishing to be bound by theory, it is believed that many of thegels resulting from dual metallocene-based bimodal polymers are due tothe large difference in viscosity that can arise between the flowcharacteristics of the polymer fraction produced from one catalyst andthe flow characteristics of the polymer fraction produced from the othercatalyst. It was found that the particle size of the solid activator(and thus, the particle size of the supported metallocene catalyst) canimpact the relative amounts of each metallocene compound on the solidactivator. For instance, metallocene compound 1 may react quicker withthe solid activator during catalyst preparation, and thuspreferentially, the smaller activator particles may contain relativelymore metallocene compound 1 and the larger activator particles maycontain relatively more metallocene compound 2. Thus, in addition togels, the particle size distribution also can significantly impactpolymer properties, such as polymer molecular weight distribution andrheological properties in both the low and high shear regions. Forinstance, it was found that larger solid activator particles (and thuslarger supported metallocene catalyst particles) often result in polymerparticles with much higher viscosities and molecular weights thansmaller particles.

By controlling the particle size distribution of the activator (and thesupported metallocene catalyst), more consistent polymer particle sizes(in powder or fluff form) can be produced, thereby resulting in ethylenepolymers with a unique combination of density, melt flow, and molecularweight properties, while also minimizing gels and improving impactstrength.

Catalyst Compositions

Disclosed herein are catalyst compositions comprising a metallocenecompound, a solid activator, and optionally, a co-catalyst. The solidactivator (or the supported metallocene catalyst) can be characterizedby a d50 average particle size in a range from 15 to 50 μm and aparticle size span ((d90−d10)/d50) in a range from 0.5 to 1.5. Referringfirst to the solid activator, which can comprise a solid oxide treatedwith an electron-withdrawing anion, examples of such materials aredisclosed in, for instance, U.S. Pat. Nos. 7,294,599, 7,601,665,7,884,163, 8,309,485, 8,623,973, and 9,023,959, which are incorporatedherein by reference in their entirety. For instance, the solid activatorcan comprise fluorided alumina, chlorided alumina, bromided alumina,sulfated alumina, fluorided silica-alumina, chlorided silica-alumina,bromided silica-alumina, sulfated silica-alumina, fluoridedsilica-zirconia, chlorided silica-zirconia, bromided silica-zirconia,sulfated silica-zirconia, fluorided silica-titania, fluorided-chloridedsilica-coated alumina, fluorided silica-coated alumina, sulfatedsilica-coated alumina, or phosphated silica-coated alumina, and thelike, as well as any combination thereof.

In one aspect, the solid activator can comprise fluorided alumina,sulfated alumina, fluorided silica-alumina, sulfated silica-alumina,fluorided silica-coated alumina, fluorided-chlorided silica-coatedalumina, sulfated silica-coated alumina, or any combination thereof. Inanother aspect, the solid activator can comprise fluorided alumina;alternatively, sulfated alumina; alternatively, fluoridedsilica-alumina; alternatively, sulfated silica-alumina; alternatively,fluorided silica-coated alumina; alternatively, fluorided-chloridedsilica-coated alumina; or alternatively, sulfated silica-coated alumina.In yet another aspect, the solid activator can comprise a fluoridedsolid oxide and/or a sulfated solid oxide.

Various processes can be used to form solid activators useful in thepresent invention. Methods of contacting the solid oxide with theelectron-withdrawing component, suitable electron withdrawing componentsand addition amounts, impregnation with metals or metal ions (e.g.,zinc, nickel, vanadium, titanium, silver, copper, gallium, tin,tungsten, molybdenum, zirconium, and the like, or combinations thereof),and various calcining procedures and conditions are disclosed in, forexample, U.S. Pat. Nos. 6,107,230, 6,165,929, 6,294,494, 6,300,271,6,316,553, 6,355,594, 6,376,415, 6,388,017, 6,391,816, 6,395,666,6,524,987, 6,548,441, 6,548,442, 6,576,583, 6,613,712, 6,632,894,6,667,274, 6,750,302, 7,294,599, 7,601,665, 7,884,163, and 8,309,485,which are incorporated herein by reference in their entirety. Othersuitable processes and procedures for preparing solid activators (e.g.,fluorided solid oxides, sulfated solid oxides, etc.) are well known tothose of skill in the art.

The catalyst composition can contain a co-catalyst. When present, theco-catalyst can include, but is not limited to, metal alkyl, ororganometal, co-catalysts, with the metal encompassing boron, aluminum,zinc, and the like. Optionally, the catalyst systems provided herein cancomprise a co-catalyst, or a combination of co-catalysts. For instance,alkyl boron, alkyl aluminum, and alkyl zinc compounds often can be usedas co-catalysts in such catalyst systems. Representative boron compoundscan include, but are not limited to, tri-n-butyl borane,tripropylborane, triethylborane, and the like, and this includecombinations of two or more of these materials. While not being limitedthereto, representative aluminum compounds (e.g., organoaluminumcompounds) can include trimethylaluminum (TMA), triethylaluminum (TEA),tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum (TIBA),tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride,diethylaluminum ethoxide, diethylaluminum chloride, and the like, aswell as any combination thereof. Exemplary zinc compounds (e.g.,organozinc compounds) that can be used as co-catalysts can include, butare not limited to, dimethylzinc, diethylzinc, dipropylzinc,dibutylzinc, dineopentylzinc, di(trimethylsilyl)zinc,di(triethylsilyl)zinc, di(triisoproplysilyl)zinc,di(triphenylsilyl)zinc, di(allyldimethylsilyl)zinc,di(trimethylsilylmethyl)zinc, and the like, or combinations thereof.Accordingly, in an aspect of this invention, the catalyst compositioncan comprise the metallocene compound (one or more than one), the solidactivator, and an organoaluminum compound, such as TMA, TEA, TIBA, andthe like, or any combination thereof.

Consistent with this disclosure, the catalyst composition can contain asingle metallocene compound, for example, any suitable bridgedmetallocene compound or any suitable unbridged metallocene compound, orany bridged metallocene compound or any unbridged metallocene compounddisclosed herein. Alternatively, the catalyst composition can be a dualcatalyst system. In such instances, the catalyst composition can containmetallocene component I comprising any suitable unbridged metallocenecompound or any disclosed herein and metallocene component II comprisingany suitable bridged metallocene compound or any disclosed herein.Whether the catalyst compositions contains a single metallocenecompound, two metallocene compounds, or more than two metallocenecompounds, the catalyst composition also can contain any suitable solidactivator or any solid activator disclosed herein (one or more thanone), and optionally, any suitable co-catalyst or any co-catalystdisclosed herein (one or more than one).

Referring first to metallocene component I, which often can comprise anunbridged zirconium or hafnium based metallocene compound containing twocyclopentadienyl groups, two indenyl groups, or a cyclopentadienyl andan indenyl group. In one aspect, metallocene component I can comprise anunbridged zirconium or hafnium based metallocene compound containing twocyclopentadienyl groups. In another aspect, metallocene component I cancomprise an unbridged zirconium or hafnium based metallocene compoundcontaining two indenyl groups. In yet another aspect, metallocenecomponent I can comprise an unbridged zirconium or hafnium basedmetallocene compound containing a cyclopentadienyl group and an indenylgroup. In still another aspect, metallocene component I can comprise anunbridged zirconium based metallocene compound containing analkyl-substituted cyclopentadienyl group and an alkenyl-substitutedindenyl group.

Metallocene component I can comprise, in particular aspects of thisinvention, an unbridged metallocene compound having formula (I):

Within formula (I), M, Cp^(A), Cp^(B), and each X are independentelements of the unbridged metallocene compound. Accordingly, theunbridged metallocene compound having formula (I) can be described usingany combination of M, Cp^(A), Cp^(B), and X disclosed herein. Unlessotherwise specified, formula (I) above, any other structural formulasdisclosed herein, and any metallocene complex, compound, or speciesdisclosed herein are not designed to show stereochemistry or isomericpositioning of the different moieties (e.g., these formulas are notintended to display cis or trans isomers, or R or S diastereoisomers),although such compounds are contemplated and encompassed by theseformulas and/or structures.

In accordance with aspects of this invention, the metal in formula (I),M, can be Zr or Hf. Thus, M can be Zr in one aspect, and M can be Hf inanother aspect. Each X in formula (I) independently can be a monoanionicligand. In some aspects, suitable monoanionic ligands can include, butare not limited to, H (hydride), BH₄, a halide, a C₁ to C₃₆ hydrocarbylgroup, a C₁ to C₆ hydrocarboxy group, a C₁ to C₃₆ hydrocarbylaminylgroup, a C₁ to C₃₆ hydrocarbylsilyl group, a C₁ to C₃₆hydrocarbylaminylsilyl group, —OBR¹ ₂, or —OSO₂R¹, wherein R¹ is a C₁ toC₃₆ hydrocarbyl group. It is contemplated that each X can be either thesame or a different monoanionic ligand. Suitable hydrocarbyl groups,hydrocarboxy groups, hydrocarbylaminyl groups, hydrocarbylsilyl groups,and hydrocarbylaminylsilyl groups are disclosed, for example, in U.S.Pat. No. 9,758,600, incorporated herein by reference in its entirety.

Generally, the hydrocarbyl group which can be an X in formula (I) can bea C₁ to C₃₆ hydrocarbyl group, including a C₁ to C₃₆ alkyl group, a C₂to C₃₆ alkenyl group, a C₄ to C₃₆ cycloalkyl group, a C₆ to C₃₆ arylgroup, or a C₇ to C₃₆ aralkyl group. For instance, each X independentlycan be a C₁ to C₁₈ alkyl group, a C₂ to C₁₈ alkenyl group, a C₄ to C₁₈cycloalkyl group, a C₆ to C₁₈ aryl group, or a C₇ to C₁₈ aralkyl group:alternatively, each X independently can be a C₁ to C₁₂ alkyl group, a C₂to C₁₂ alkenyl group, a C₄ to C₁₂ cycloalkyl group, a C₆ to C₁₂ arylgroup, or a C₇ to C₁₀ aralkyl group; alternatively, each X independentlycan be a C₁ to C₁₀ alkyl group, a C₂ to C₁₀ alkenyl group, a C₄ to C₁₀cycloalkyl group, a C₆ to C₁₀ aryl group, or a C₇ to C₁₀ aralkyl group;or alternatively, each X independently can be a C₁ to C₈ alkyl group, aC₂ to C₈ alkenyl group, a C₅ to C₈ cycloalkyl group, a C₆ to C₈ arylgroup, or a C₇ to C₈ aralkyl group.

In particular aspects of this invention, each X independently can be ahalide or a C₁ to C₁₈ hydrocarbyl group. For instance, each X can be Cl.

In formula (I). Cp^(A) and Cp^(B) independently can be a substituted orunsubstituted cyclopentadienyl or indenyl group. In one aspect, Cp^(A)and Cp^(B) independently can be an unsubstituted cyclopentadienyl orindenyl group. Alternatively. Cp^(A) and Cp^(B) independently can be asubstituted indenyl or cyclopentadienyl group, for example, having up to5 substituents.

If present, each substituent on Cp^(A) and Cp^(B) independently can beH, a halide, a C₁ to C₃₆ hydrocarbyl group, a C₁ to C₃₆ halogenatedhydrocarbyl group, a C₁ to C₃₆ hydrocarboxy group, or a C₁ to C₃₆hydrocarbylsilyl group. Importantly, each substituent on Cp^(A) and/orCp^(B) can be either the same or a different substituent group.Moreover, each substituent can be at any position on the respectivecyclopentadienyl or indenyl ring structure that conforms with the rulesof chemical valence. In an aspect, the number of substituents on Cp^(A)and/or on Cp^(B) and/or the positions of each substituent on Cp^(A)and/or on Cp^(B) are independent of each other. For instance, two ormore substituents on Cp^(A) can be different, or alternatively, eachsubstituent on Cp^(A) can be the same. Additionally or alternatively,two or more substituents on Cp^(B) can be different, or alternatively,all substituents on Cp^(B) can be the same. In another aspect, one ormore of the substituents on Cp^(A) can be different from the one or moreof the substituents on Cp^(B), or alternatively, all substituents onboth Cp^(A) and/or on Cp^(B) can be the same. In these and otheraspects, each substituent can be at any position on the respectivecyclopentadienyl or indenyl ring structure. If substituted, Cp^(A)and/or Cp^(B) independently can have one substituent, or twosubstituents, or three substituents, or four substituents, and so forth.

Suitable hydrocarbyl groups, halogenated hydrocarbyl groups,hydrocarboxy groups, and hydrocarbylsilyl groups that can besubstituents are disclosed, for example, in U.S. Pat. No. 9,758,600,incorporated herein by reference in its entirety. For instance, thehalogenated hydrocarbyl group indicates the presence of one or morehalogen atoms replacing an equivalent number of hydrogen atoms in thehydrocarbyl group. The halogenated hydrocarbyl group often can be ahalogenated alkyl group, a halogenated alkenyl group, a halogenatedcycloalkyl group, a halogenated aryl group, or a halogenated aralkylgroup. Representative and non-limiting halogenated hydrocarbyl groupsinclude pentafluorophenyl, trifluoromethyl (CF₃), and the like.

Illustrative and non-limiting examples of unbridged metallocenecompounds having formula (I) and/or suitable for use as metallocenecomponent I can include the following compounds (Ph=phenyl):

and the like, as well as combinations thereof.

Metallocene component I is not limited solely to unbridged metallocenecompounds such as described above. Other suitable unbridged metallocenecompounds are disclosed in U.S. Pat. Nos. 7,199,073, 7,226,886,7,312,283, and 7,619,047, which are incorporated herein by reference intheir entirety.

Referring now to metallocene component II, which can be a bridgedmetallocene compound. In one aspect, for instance, metallocene componentII can comprise a bridged zirconium or hafnium based metallocenecompound. In another aspect, metallocene component II can comprise abridged zirconium or hafnium based metallocene compound with an alkenylsubstituent. In yet another aspect, metallocene component II cancomprise a bridged zirconium or hafnium based metallocene compound withan alkenyl substituent and a fluorenyl group. In still another aspect,metallocene component II can comprise a bridged zirconium or hafniumbased metallocene compound with a cyclopentadienyl group and a fluorenylgroup, and with an alkenyl substituent on the bridging group and/or onthe cyclopentadienyl group. Further, metallocene component II cancomprise a bridged metallocene compound having an aryl group substituenton the bridging group.

Metallocene component II can comprise, in particular aspects of thisinvention, a bridged metallocene compound having formula (II):

Within formula (II), M, Cp, R^(X), R^(Y), E, and each X are independentelements of the bridged metallocene compound. Accordingly, the bridgedmetallocene compound having formula (II) can be described using anycombination of M, Cp, R^(X), R^(Y), E, and X disclosed herein. Theselections for M and each X in formula (II) are the same as thosedescribed herein above for formula (I). In formula (II), Cp can be asubstituted cyclopentadienyl, indenyl, or fluorenyl group. In oneaspect. Cp can be a substituted cyclopentadienyl group, while in anotheraspect. Cp can be a substituted indenyl group.

In some aspects, Cp can contain no additional substituents, e.g., otherthan bridging group E, discussed further herein below. In other aspects,Cp can be further substituted with one substituent, or two substituents,or three substituents, or four substituents, and so forth. If present,each substituent on Cp independently can be H, a halide, a C₁ to C₃₆hydrocarbyl group, a C₁ to C₃₆ halogenated hydrocarbyl group, a C₁ toC₃₆ hydrocarboxy group, or a C₁ to C₃₆ hydrocarbylsilyl group.Importantly, each substituent on Cp can be either the same or adifferent substituent group. Moreover, each substituent can be at anyposition on the respective cyclopentadienyl, indenyl, or fluorenyl ringstructure that conforms with the rules of chemical valence. In general,any substituent on Cp, independently, can be H or any halide, C₁ to C₃₆hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbyl group, C₁ to C₃₆hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl group described herein(e.g., as pertaining to substituents on Cp^(A) and Cp^(B) in formula(I)).

Similarly. R^(X) and R^(Y) in formula (II) independently can be H or anyhalide, C₁ to C₃₆ hydrocarbyl group, C₁ to C₃₆ halogenated hydrocarbylgroup, C₁ to C₃₆ hydrocarboxy group, or C₁ to C₃₆ hydrocarbylsilyl groupdisclosed herein (e.g., as pertaining to substituents on Cp^(A) andCp^(B) in formula (I)). In one aspect, for example, R^(X) and R^(Y)independently can be H or a C₁ to C₁₂ hydrocarbyl group. In anotheraspect, R^(X) and R^(Y) independently can be a C₁ to C₁₀ hydrocarbylgroup. In yet another aspect, R^(X) and R^(Y) independently can be H,Cl, CF₃, a methyl group, an ethyl group, a propyl group, a butyl group(e.g., t-Bu), a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, an ethenyl group, a propenyl group,a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, a tolylgroup, a benzyl group, a naphthyl group, a trimethylsilyl group, atriisopropylsilyl group, a triphenylsilyl group, or anallyldimethylsilyl group, and the like. In still another aspect, R^(X)and R^(Y) independently can be a methyl group, an ethyl group, a propylgroup, a butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, a nonyl group, a decyl group, an ethenyl group, a propenylgroup, a butenyl group, a pentenyl group, a hexenyl group, a heptenylgroup, an octenyl group, a nonenyl group, a decenyl group, a phenylgroup, a tolyl group, or a benzyl group.

Bridging group E in formula (II) can be a bridging group having theformula >E^(A)R^(A)R^(B), wherein E^(A) can be C, Si, or Ge, and R^(A)and R^(B) independently can be H or a C₁ to C₁₈ hydrocarbyl group. Insome aspects of this invention, R^(A) and R^(B) independently can be aC₁ to C₁₂ hydrocarbyl group; alternatively, R^(A) and R^(B)independently can be a C₁ to C₈ hydrocarbyl group; alternatively, R^(A)and R^(B) independently can be a phenyl group, a C₁ to C₈ alkyl group,or a C₃ to C₈ alkenyl group; alternatively, R^(A) and R^(B)independently can be a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, a decyl group, an ethenyl group, a propenyl group,a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, anoctenyl group, a nonenyl group, a decenyl group, a phenyl group, acyclohexylphenyl group, a naphthyl group, a tolyl group, or a benzylgroup; or alternatively, R^(A) and R^(B) independently can be a methylgroup, an ethyl group, a propyl group, a butyl group, a pentyl group, ahexyl group, a propenyl group, a butenyl group, a pentenyl group, ahexenyl group, a phenyl group, or a benzyl group. In these and otheraspects, R^(A) and R^(B) can be either the same or different.

Illustrative and non-limiting examples of bridged metallocene compoundshaving formula (II) and/or suitable for use as metallocene component IIcan include the following compounds (Me=methyl, Ph=phenyl;t-Bu=tert-butyl):

and the like, as well as combinations thereof.

Metallocene component II is not limited solely to the bridgedmetallocene compounds such as described above. Other suitable bridgedmetallocene compounds are disclosed in U.S. Pat. Nos. 7,026,494,7,041,617, 7,226,886, 7,312,283, 7,517,939, and 7,619,047, which areincorporated herein by reference in their entirety.

According to an aspect of this invention, the weight ratio ofmetallocene component I to metallocene component II in the catalystcomposition can be in a range from 10:1 to 1:10, from 8:1 to 1:8, from5:1 to 1:5, from 4:1 to 1:4, from 3:1 to 1:3; from 2:1 to 1:2, from1.5:1 to 1:1.5, from 1.25:1 to 1:1.25, or from 1.1:1 to 1:1.1. Inanother aspect, metallocene component I is the major component of thecatalyst composition, and in such aspects, the weight ratio ofmetallocene component I to metallocene component II in the catalystcomposition can be in a range from 10:1 to 1:1, from 5:1 to 1.1:1, from2:1 to 1.1:1, or from 1.8:1 to 1.1:1.

It is contemplated herein that the catalyst composition can comprise ametallocene compound (or metallocene component I and metallocenecomponent II), a solid activator, and a co-catalyst (e.g., anorganoaluminum compound), wherein this catalyst composition issubstantially free of aluminoxanes, organoboron or organoboratecompounds, ionizing ionic compounds, and/or other similar materials;alternatively, substantially free of aluminoxanes, alternatively,substantially free or organoboron or organoborate compounds; oralternatively, substantially free of ionizing ionic compounds. In theseaspects, the catalyst composition has catalyst activity, discussedherein, in the absence of these additional materials. For example, acatalyst composition of the present invention can consist essentially ofthe metallocene compound (or metallocene component I and metallocenecomponent II), the solid activator, and the organoaluminum compound,wherein no other materials are present in the catalyst composition whichwould increase/decrease the activity of the catalyst composition by morethan 10% from the catalyst activity of the catalyst composition in theabsence of said materials.

Catalyst compositions of the present invention generally have a catalystactivity greater than 150 grams of ethylene polymer (homopolymer and/orcopolymer, as the context requires) per gram of solid activator per hour(abbreviated g/g/hr). In another aspect, the catalyst activity can begreater than 250, greater than 350, or greater than 500 g/g/hr. Yet, inanother aspect, the catalyst activity can be greater than 700 g/g/hr,greater than 1000 g/g/hr, or greater than 2000 g/g/hr. and often as highas 5000-10,000 g/g/hr. Illustrative and non-limiting ranges for thecatalyst activity include from 150 to 10,000, from 500 to 7500, or from1000 to 5000 g/g/hr, and the like. These activities are measured underslurry polymerization conditions, with a triisobutylaluminumco-catalyst, using isobutane as the diluent, at a polymerizationtemperature of 95° C. and a reactor pressure of 590 psig. Moreover, insome aspects, the solid activator comprise sulfated alumina, fluoridedsilica-alumina, or fluorided silica-coated alumina, although not limitedthereto.

This invention further encompasses methods of making these catalystcompositions, such as, for example, contacting the respective catalystcomponents in any order or sequence. In one aspect, for example, thecatalyst composition can be produced by a process comprising contacting,in any order, the metallocene compound, the solid activator, and theco-catalyst, while in another aspect, the catalyst composition can beproduced by a process comprising contacting, in any order, metallocenecomponent I, metallocene component II, the solid activator, and theco-catalyst.

In the catalyst compositions disclosed herein, the solid activator (orthe supported metallocene catalyst) can be characterized by a d50average particle size in a range from 15 to 50 μm and a particle sizespan ((d90−d10)/d50) in a range from 0.5 to 1.5. In one aspect, the d50average particle size can be in a range from 15 to 40 μm or from 15 to25 μm, while in another aspect, the d50 particle size can be from 20 to30 μm, and in another aspect, the d50 particle size can be from 17 to 40μm or from 17 to 27 μm, and in still another aspect, the d50 particlesize can be from 17 to 25 μm. Likewise, the span ((d90−d10)/d50) can bein a range from 0.5 to 1.2 in one aspect, from 0.6 to 1.4 or from 0.6 to1.3 in another aspect, from 0.6 to 1.1 in yet another aspect, and from0.7 to 1.4 or from 0.7 to 1.2 in still another aspect. The solidactivator (or the supported metallocene catalyst) also can have any ofthe particle attributes listed below and in any combination, unlessindicated otherwise.

The solid activator (or the supported metallocene catalyst) can have ad10 particle size of greater than or equal to 10 μm; alternatively,greater than or equal to 11 μm; alternatively, greater than or equal to12 μm; alternatively, in a range from 10 to 20 μm; or alternatively in arange from 10 to 18 μm. Additionally or alternatively, the solidactivator (or the supported metallocene catalyst) can have a d95particle size of less than or equal to 65 μm; alternatively, less thanor equal to 60 μm; alternatively, in a range from 25 to 65 μm; oralternatively, in a range from 28 to 60 μm.

While not limited thereto, the solid activator (or the supportedmetallocene catalyst) can be further characterized by a ratio ofd90/d10, which often ranges from 1.5 to 5. In some aspects, the ratio ofd90/d10 can be from 1.5 to 4, from 1.5 to 3, from 1.8 to 5, from 1.8 to4, or from 1.8 to 3.

Typically, a very small amount of the solid activator (or the supportedmetallocene catalyst) has a particle size of less than 10 μm. In oneaspect, the amount is less than or equal to 15% or less than or equal to10%, while in another aspect, the amount is less than or equal to 8% orless than or equal to 5%, and in yet another aspect, the amount is lessthan or equal to 2%. Likewise, a very small amount of the solidactivator (or the supported metallocene catalyst) has a particle size ofgreater than 45 μm. In one aspect, the amount is less than or equal to20%, while in another aspect, the amount is less than or equal to 15% orless than or equal to 10%, and in yet another aspect, the amount is lessthan or equal to 5% or less than or equal to 2%. In contrast, a vastmajority of the solid activator (or the supported metallocene catalyst)has a particle size of less than 50 μm. For instance, at least 85% ofthe solid activator (or the supported metallocene catalyst) has aparticle size of less than 50 μm, while in further aspects, the amountof the solid activator (or the supported metallocene catalyst) with aparticle size of less than 50 μm can be at least 88%, at least 900%, orat least 95%.

Polymerization Processes

Olefin polymers (e.g., ethylene polymers) can be produced from thedisclosed metallocene catalyst compositions using any suitablepolymerization process using various types of polymerization reactors,polymerization reactor systems, and polymerization reaction conditions.A polymerization process can comprise contacting the catalystcomposition (any metallocene-based catalyst composition disclosedherein) with an olefin monomer and an optional olefin comonomer in apolymerization reactor system comprising a loop slurry reactor underpolymerization conditions to produce an olefin polymer. This inventionalso encompasses any olefin polymers (e.g., ethylene polymers) producedby the polymerization processes disclosed herein.

In one aspect, the polymerization reactor system can comprise only oneloop slurry reactor (a single loop slurry reactor). However, in anotheraspect, the polymerization reactor system can comprise two or morereactors, at least one of which is the loop slurry reactor. The otherreactor(s) in the polymerization reactor system can be another slurryreactor (dual loop slurry), a gas-phase reactor, a solution reactor, ora combination thereof. The production of polymers in multiple reactorscan include several stages in at least two separate polymerizationreactors interconnected by a transfer device making it possible totransfer the polymers resulting from the first polymerization reactorinto the second reactor. The desired polymerization conditions in one ofthe reactors can be different from the operating conditions of the otherreactor(s). Alternatively, polymerization in multiple reactors caninclude the manual transfer of polymer from one reactor to subsequentreactors for continued polymerization. The multiple reactors can beoperated in series, in parallel, or both. Accordingly, the presentinvention encompasses polymerization reactor systems comprising a singlereactor, comprising two reactors, and comprising more than two reactors,wherein at least one is a loop slurry reactor.

In a loop slurry reactor, monomer, diluent, catalyst system, andcomonomer (if used) can be continuously fed to a loop reactor wherepolymerization occurs. Generally, continuous processes can comprise thecontinuous introduction of monomer/comonomer, a catalyst system, and adiluent into a polymerization reactor and the continuous removal fromthis reactor of a suspension comprising polymer particles (powder orfluff) and the diluent. Reactor effluent can be flashed to remove thesolid polymer from the liquids that comprise the diluent, monomer and/orcomonomer. Various technologies can be used for this separation stepincluding, but not limited to, flashing that can include any combinationof heat addition and pressure reduction, separation by cyclonic actionin either a cyclone or hydrocyclone, or separation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess) is disclosed, for example, in U.S. Pat. Nos. 3,248,179,4,501,885, 5,565.175, 5,575,979, 6,239,235, 6,262,191, 6.833,415, and8,822,608, each of which is incorporated herein by reference in itsentirety.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under reaction conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used.

The polymerization reactor system can further comprise any combinationof at least one raw material feed system, at least one feed system forthe catalyst system or catalyst components, and/or at least one polymerrecovery system. Suitable reactor systems can further comprise systemsfor feedstock purification, catalyst storage and preparation, extrusion,reactor cooling, polymer recovery, fractionation, recycle, storage,loadout, laboratory analysis, and process control. Depending upon thedesired properties of the olefin polymer, hydrogen can be added to thepolymerization reactor system as needed (e.g., continuously, pulsed,etc.).

Polymerization conditions that can be controlled for efficiency and toprovide desired polymer properties can include temperature, pressure,and the concentrations of various reactants. Polymerization temperaturecan affect catalyst productivity, polymer molecular weight, andmolecular weight distribution. Various polymerization conditions can beheld substantially constant, for example, for the production of aparticular grade of the olefin polymer (or ethylene polymer). A suitablepolymerization temperature can be any temperature below thede-polymerization temperature according to the Gibbs Free energyequation. Typically, this includes from 60° C. to 280° C., for example,or from 60° C. to 120° C., depending upon the type of polymerizationreactor. In some loop reactor systems, the polymerization temperaturegenerally can be within a range from 70° C. to 100° C., or from 75° C.to 95° C. Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor is typically less than 1000 psig (6.9 MPa) and greater than200 psig (1.4 MPa).

Olefin monomers that can be employed with the catalyst compositions andslurry-based polymerization processes of this invention typically caninclude olefin compounds having from 2 to 30 carbon atoms per moleculeand having at least one olefinic double bond, such as ethylene orpropylene. In an aspect, the olefin monomer can comprise a C₂-C₂₀olefin; alternatively, a C₂-C₂₀ alpha-olefin; alternatively, a C₂-C₁₀olefin; alternatively, a C₂-C₁₀ alpha-olefin; alternatively, the olefinmonomer can comprise ethylene; or alternatively, the olefin monomer cancomprise propylene (e.g., to produce a polypropylene homopolymer or apropylene-based copolymer).

When a copolymer (or alternatively, a terpolymer) is desired, the olefinmonomer and the olefin comonomer independently can comprise, forexample, a C₂-C₂₀ alpha-olefin. In some aspects, the olefin monomer cancomprise ethylene or propylene, which is copolymerized with at least onecomonomer (e.g., a C₂-C₂₀ alpha-olefin, a C₃-C₂₀ alpha-olefin, etc.).According to one aspect of this invention, the olefin monomer used inthe polymerization process can comprise ethylene. In this aspect, thecomonomer can comprise a C₃-C₁₀ alpha-olefin; alternatively, thecomonomer can comprise 1-butene, I-pentene, 1-hexene, 1-octene,1-decene, styrene, or any combination thereof; alternatively, thecomonomer can comprise 1-butene, 1-hexene, 1-octene, or any combinationthereof; alternatively, the comonomer can comprise 1-butene;alternatively, the comonomer can comprise 1-hexene; or alternatively,the comonomer can comprise 1-octene.

An illustrative and non-limiting example of an ethylene polymercomposition that can be produced using the catalysts and processesdisclosed herein can have a d50 average particle size in a range from150 to 600 μm, a particle size span ((d90-d10)/d50) in a range from 0.5to 1.6, less than or equal to 20% of the composition with a particlesize of less than 100 μm, and less than or equal to 5% of thecomposition with a particle size of greater than 1000 μm. The ethylenepolymer composition can be in powder form (also referred to as fluff),prior to mixing and homogenizing to form typical resin pellets or beads.

Often, the d50 average particle size can fall within a range from 150 to450 μm, from 150 to 325 μm, from 150 to 300 μm, from 175 to 325 μm, from175 to 275 μm, from 200 to 400 μm, or from 200 to 275 μm, and the span((d90−d10)/d50) can fall within a range from 0.75 to 1.5, from 1 to 1.6,from 1.1 to 1.6, or from 1.1 to 1.5. Additionally or alternatively, theamount of the composition having a particle size of greater than 1000 μmcan be less than or equal to 5%, such as less than or equal to 3%, lessthan or equal to 2%, or less than or equal to 1%. Additionally oralternatively, the amount of the composition having a particle size ofless than 100 μm can be less than or equal to 20%, such as less than orequal to 10%, less than or equal to 5%, from 1 to 10%, or from 1 to 5%.

Optionally, the ethylene polymer composition (in powder or fluff form)can be further characterized by a d90 particle size from 300 to 800 μm(e.g., from 300 to 600 μm, from 350 to 550 μm, from 375 to 525 μm, from400 to 750 μm, or from 400 to 500 μm) and/or by a ratio of d90/d10 from2 to 5 (e.g., from 2 to 4, from 2.2 to 3.8, from 2.4 to 5, from 2.4 to3.6, or from 2.7 to 3.3).

While not limited thereto, the HLMI of the composition can be in a rangefrom 4 to 10 g/10 min; alternatively, from 4 to 9 g/10 min;alternatively, from 4 to 8 g/10 min; alternatively, from 5 to 10 g/10min; alternatively, from 5 to 9 g/10 min; or alternatively, from 5 to 8g/10 min. Likewise, the density of the composition is not particularlylimited, generally ranging from 0.944 to 0.955 g/cm³, and additionalillustrative ranges include from 0.944 to 0.952, from 0.945 to 0.955,from 0.945 to 0.953, from 0.945 to 0.95, from 0.946 to 0.955, or from0.946 to 0.952 g/cm³, and the like.

It should be noted that the metallocene-based catalysts produced by thesolid activators of this invention tend to produce a more homogeneousdistribution of polymer particles, in terms of size and also in terms ofcomonomer incorporation. The narrow distribution of polymer particlesize significantly helps the flow of the polymer powder, reducingfouling, packing, and enhancing transfer in downstream operations. Thisis partly because the polymer powder has less tendency to segregate uponhandling. In segregation test ASTM 6941, this results in less than 10%,and in some cases, less than 7%, less than 5% or less than 3% change inthe mean size in samples taken from the top to the bottom of the settledpolymer bed. Similarly, the change in d10 value from top to bottom isless than 20%, and more often can be less than 15%, less than 10%, orless than 7%. Likewise, the change in d90 value can be less than 5%;alternatively, less than 3%; or alternatively, less than 2%.

The coefficient of variation in the segregation test for the mean shouldbe less than 7%, and can be less than 6%, less than 5%, less than 4%, orless than 3%, in some aspects. For the d10 value, it should be less than25%, and can be less 20%, less than 15%, less than 10%, or less than 7%,in some aspects. For the d90, the coefficient of variation should beless than 5%, and can be less than 4%, or less than 3%, in some aspects.Further, for the d50 value, the coefficient of variation should be lessthan 8%, and can be less than 7%, less than 6%, less than 5%, less than4%, or less than 3%, in some aspects.

Another consequence of polymer particle heterogeneity is that thedensity of each particle can vary widely. However, the polymer particles(also referred to as powder or fluff) of this invention vary less than0.035 g/cm³ in one aspect, less than 0.03 g/cm³ in another aspect, lessthan 0.02 g/cm³ in another aspect, less than 0.015 g/cm³ in anotheraspect, less than 0.01 g/cm³ in yet another aspect, or less than 0.006g/cm³ in still another aspect.

Olefin Polymers

This invention is also directed to, and encompasses, the olefin polymersproduced by any of the polymerization processes disclosed herein. Olefinpolymers encompassed herein can include any polymer produced from anyolefin monomer and optional comonomer(s) described herein. For example,the olefin polymer can comprise an ethylene homopolymer, an ethylenecopolymer (e.g., ethylene/α-olefin, ethylene/l-butene,ethylene/I-hexene, ethylene/1-octene, etc.), a propylene homopolymer, apropylene copolymer, an ethylene terpolymer, a propylene terpolymer, andthe like, including any combinations thereof. In one aspect, the olefinpolymer can comprise an ethylene homopolymer, an ethylene/1-butenecopolymer, an ethylene/1-hexene copolymer, and/or an ethylene/1-octenecopolymer, while in another aspect, the olefin polymer can comprise anethylene/1-hexene copolymer.

If the resultant polymer produced in accordance with the presentinvention is, for example, an ethylene polymer, its properties can becharacterized by various analytical techniques known and used in thepolyolefin industry. Articles of manufacture can be formed from, and/orcan comprise, the olefin polymers (e.g., ethylene polymers) of thisinvention, whose typical properties are provided below.

The densities of ethylene-based polymers disclosed herein often aregreater than or equal to 0.90 g/cm³, and less than or equal to 0.97g/cm³. Yet, in particular aspects, the density can be in a range from0.91 to 0.965 g/cm³, from 0.92 to 0.96 g/cm³, from 0.93 to 0.955 g/cm³,or from 0.94 to 0.955 g/cm³. While not being limited thereto, theethylene polymer can have a high load melt index (HLMI) in a range from0 to 100 g/10 min; alternatively, from 1 to 80 g/10 min; alternatively,from 2 to 40 g/10 min; alternatively, from 2 to 30 g/10 min;alternatively, from 1 to 20 g/10 min; or alternatively, from 50 to 100g/10 min. In an aspect, ethylene polymers described herein can have aratio of Mw/Mn, or the polydispersity index, in a range from 2 to 40,from 5 to 40, from 7 to 25, from 8 to 15, from 2 to 10, from 2 to 6, orfrom 2 to 4. Additionally or alternatively, the ethylene polymer canhave a weight-average molecular weight (Mw) in a range from 75,000 to700,000, from 75,000 to 200,000, from 100,000 to 500,000, from 150,000to 350,000, or from 200,000 to 320,000 g/mol. Moreover, the olefinpolymers can be produced with a single or dual metallocene catalystsystem containing zirconium and/or hafnium. In such instances, theolefin or ethylene polymer can contain no measurable amount of Mg, V,Ti, and Cr, i.e., less than 0.1 ppm by weight. In further aspects, theolefin or ethylene polymer can contain, independently, less than 0.08ppm, less than 0.05 ppm, or less than 0.03 ppm, of Mg, V, Ti, and Cr.

It was surprisingly found that the particular size distribution of thesolid activator (and thus, the particle size distribution of thesupported metallocene catalyst, for instance, containing two metallocenecompounds) significantly impacts the molecular weight and rheologicalproperties of the resulting ethylene polymer. For instance, it was foundthat larger solid activator particles (and thus larger supportedmetallocene catalyst particles) often result in polymer particles withhigher viscosities and higher molecular weights than smaller particles,and further, these can often lead to gels due to their high viscosityand poor dispersibility.

An illustrative and non-limiting example of a particular ethylenepolymer (e.g., an ethylene/α-olefin copolymer)—produced using the solidactivator with a d50 from 15 to 50 μm and a particle size distributionfrom 0.5 to 1.5—has a high load melt index (HLMI) in a range from 4 to10 g/10 min, a density in a range from 0.944 to 0.955 g/cm³, and ahigher molecular weight component and a lower molecular weightcomponent. The higher molecular weight component can have a Mn in arange from 280,000 to 440,000 g/mol, while the lower molecular weightcomponent can have a Mw in a range from 30,000 to 45,000 g/mol, and aratio of Mz/Mw in a range from 2.3 to 3.4. While not limited thereto,the ethylene polymer can be in the form of pellets or beads. Thisillustrative and non-limiting example of a particular ethylene polymerconsistent with the present invention also can have any of the polymerproperties listed below and in any combination, unless indicatedotherwise.

The ethylene polymer can comprise a high or higher molecular weight(HMW) component (or a first component) and a low or lower molecularweight (LMW) component (or a second component). These component termsare relative, are used in reference to each other, and are not limitedto the actual molecular weights of the respective components. Themolecular weight characteristics of these LMW and HMW components aredetermined by deconvoluting the composite (overall polymer) molecularweight distribution (e.g., determined using gel permeationchromatography). The amount of the lower molecular weight (LMW)component, based on the total polymer, is not limited to any particularrange. Generally, however, the amount of the lower molecular weightcomponent can be in a range from 56 to 72 wt. %, from 56 to 70 wt. %,from 58 to 72 wt. %, from 58 to 70 wt. %, or from 60 to 68 wt. %.

The higher molecular weight component can have a Mn in a range from280,000 to 440,000 g/mol. For instance, the Mn can fall within a rangefrom 280,000 to 425,000; alternatively, from 280.000 to 400,000;alternatively, from 290,000 to 410,000; alternatively, from 300,000 to440.000, or alternatively, from 300,000 to 400,000 g/mol. Additionallyor alternatively, the higher molecular weight component can have arelatively narrow molecular weight distribution, which can be quantifiedby a ratio of Mw/Mn in from 1.6 to 2.4 in one aspect, from 1.7 to 2.4(or from 1.7 to 2.3) in another aspect, from 1.8 to 2.4 (or from 1.8 to2.3) in yet another aspect, or from 1.9 to 2.4 (or from 1.9 to 2.3) instill another aspect. Additionally or alternatively, the highermolecular weight component can have a Mz in a range from 900.000 to1,600,000 g/mol, although not limited thereto. Typical ranges for the Mzof the higher molecular weight component can include, but are notlimited to, from 1,000,000 to 1,500,000, from 1,000,000 to 1,400,000,from 1,100,00) to 1,600,000, or from 1,100,000 to 1,500,000 g/mol.

The lower molecular weight component of the ethylene polymer can have aMw in a range from 30,000 to 45,000 g/mol (or from 30,000 to 43,000, orfrom 30,000 to 41,000, or from 31,000 to 45,000, or from 31,000 to42.000, or from 31.000 to 40,000, or from 32,000 to 44,000, or from32,000 to 42,000 g/mol), and a ratio of Mz/Mw in a range from 2.3 to 3.4(or from 2.3 to 3.2, or from 2.35 to 3.0, or from 2.4 to 3.3, or from2.4 to 3.2, or from 2.4 to 3.1). Additionally or alternatively, thelower molecular weight component can have a Mn that falls within a rangefrom 4,000 to 10,000 g/mol, such as from 4,000 to 9,000, from 5,000 to10,000, from 5,000 to 9,000, or from 5,500 to 8,500 g/mol. Additionallyor alternatively, the lower molecular weight component can have a Mzthat falls within a range from 70.000 to 130.000 g/mol, such as from70,000 to 115,000, from 75,000 to 130,000, from 75,000 to 120.000, orfrom 75,000 to 115,000 g/mol.

The density of the ethylene-based polymer can range from 0.944 to 0.955g/cm³. In one aspect, the density can range from 0.944 to 0.952, from0.945 to 0.955 in another aspect, from 0.945 to 0.953 in another aspect,from 0.945 to 0.95 in another aspect, from 0.946 to 0.955 in yet anotheraspect, or from 0.946 to 0.952 g/cm³ in still another aspect.

The ethylene polymer has a very low melt index, as indicated by the highload melt index (HLMI) in a range from 4 to 10 g/10 min. In someaspects, the HLMI of the ethylene polymer can fall within a range from 4to 9 or from 4 to 8 g/10 min. In other aspects, the HLMI of the ethylenepolymer can fall within a range from 5 to 10, from 5 to 9, or from 5 to8 g/10 min.

In an aspect, the ethylene polymer (inclusive of the higher and lowermolecular weight components) can have a Mw in a range from 230,000 to330,000, from 230,000 to 320,000, from 240,000 to 330,000, or from240,000 to 320,000 g/mol. The ethylene polymer has a relatively broadmolecular weight distribution, often with a ratio of Mw/Mn in a rangefrom 20 to 45. For instance, the ratio of Mw/Mn of the polymer can befrom 20 to 42; alternatively, from 22 to 44; alternatively, from 25 to45; or alternatively, from 25 to 42.

The ethylene polymer can have a CY-a parameter of from 0.45 to 0.65,from 0.47 to 0.63, from 0.47 to 0.61, from 0.48 to 0.6, from 0.5 to0.65, from 0.5 to 0.63, or from 0.5 to 0.6, and the like. Additionallyor alternatively, the ethylene polymer can have a relaxation time(Tau(eta) or τ(η)) in a range from 1.5 to 4, from 1.5 to 3.7, from 2 to4, or from 2 to 3.6 sec. Additionally or alternatively, the ethylenepolymer can have a viscosity at 100 sec⁻¹ (eta @ 100 or η @ 100) at 190°C. in a range from 2000 to 3600, from 2000 to 3500, from 2100 to 3600,or from 2100 to 3500 Pa-sec. Additionally or alternatively, the ethylenepolymer can have a ratio of viscosity at 0.1 sec⁻¹ to viscosity at 100sec⁻¹ (η 169 0.1/η @100) in a range from 38 to 72, from 40 to 68, from46 to 68, or from 52 to 72, and the like. These rheological parametersare determined from viscosity data measured at 190° C. and using theCarreau-Yasuda (CY) empirical model described herein.

In an aspect, the ethylene polymer described herein can be a reactorproduct (e.g., a single reactor product), for example, not apost-reactor blend of two polymers, for instance, having differentmolecular weight characteristics. As one of skill in the art wouldreadily recognize, physical blends of two different polymer resins canbe made, but this necessitates additional processing and complexity notrequired for a reactor product.

Moreover, the ethylene polymer can be produced with dual metallocenecatalyst systems containing zirconium and/or hafnium, as discussedherein. Ziegler-Natta and chromium based catalysts systems are notrequired. Therefore, the ethylene polymer can contain no measurableamount of chromium or titanium or vanadium or magnesium (catalystresidue), i.e., less than 0.1 ppm by weight. In some aspects, theethylene polymer can contain, independently, less than 0.08 ppm, lessthan 0.05 ppm, or less than 0.03 ppm, of chromium (or titanium, orvanadium, or magnesium).

Consistent with aspects of this disclosure, any olefin polymer (orethylene polymer) described herein can have very few gels, characterizedby a film gel count of less than 100 gels per ft² of 25 micron film. Infurther aspects, the film gel count can be less than 50, less than 25,less than 10, or less than 5 gels per ft² of 25 micron film. Herein,gels encompass any film defect having a size greater than 200 microns.The gel testing procedure and equipment are described in the examplesthat follow.

Articles and Products

Articles of manufacture can be formed from, and/or can comprise, theolefin polymers (e.g., ethylene polymers) of this invention and,accordingly, are encompassed herein. For example, articles which cancomprise the polymers of this invention can include, but are not limitedto, an agricultural film, an automobile part, a bottle, a container forchemicals, a drum, a fiber or fabric, a food packaging film orcontainer, a food service article, a fuel tank, a geomembrane, ahousehold container, a liner, a molded product, a medical device ormaterial, an outdoor storage product (e.g., panels for walls of anoutdoor shed), outdoor play equipment (e.g., kayaks, bases forbasketball goals), a pipe, a sheet or tape, a toy, or a traffic barrier,and the like. Various processes can be employed to form these articles.Non-limiting examples of these processes include injection molding, blowmolding, rotational molding, film extrusion, sheet extrusion, profileextrusion, thermoforming, and the like. Additionally, additives andmodifiers often are added to these polymers in order to providebeneficial polymer processing or end-use product attributes. Suchprocesses and materials are described in Modern Plastics Encyclopedia,Mid-November 1995 Issue, Vol. 72, No. 12; and Film ExtrusionManual—Process, Materials, Properties, TAPPI Press, 1992; thedisclosures of which are incorporated herein by reference in theirentirety. In some aspects of this invention, an article of manufacturecan comprise any of olefin polymers (or ethylene polymers) describedherein, and the article of manufacture can be or can comprise a film,such as a blown film.

Films disclosed herein, whether cast or blown, can be any thickness thatis suitable for the particular end-use application, and often, theaverage film thickness can be in a range from 0.25 to 25 mils, or from0.4 to 20 mils. For certain film applications, typical averagethicknesses can be in a range from 0.5 to 8 mils, from 0.8 to 5 mils,from 0.7 to 2 mils, or from 0.7 to 1.5 mils.

In an aspect and unexpectedly, the films (e.g. blown films) can haveexcellent dart impact strength, particular in view of the density of thepolymer. As an example, the ethylene polymer with a HLMI from 4 to 10g/10 min, a density from 0.944 to 0.955 g/cm³, a HMW component with a Mnfrom 280,000 to 440.000 g/mol, and a LMW component with a Mw from 30,000to 45,000 g/mol and a ratio of Mz/Mw from 2.3 to 3.4, can have a dartimpact greater than or equal to 150 g/mil, greater than or equal to 200g/mil, or greater than or equal to 250 g/mil, and often can range up to500-750 g/mil or more. For many film applications, the upper limit ondart impact is not determined, so long as the dart impact exceeds aparticular minimal value or threshold. Nonetheless, the dart impactvalues often fall within a range from 150 to 750 g/mil, from 250 to 600g/mil, or from 300 to 700 g/mil.

The film products encompassed herein also can be characterized by verylow levels of gels, typically having a film gel count of less than 100gels per ft² of 25 micron film, and more often, the film gel count isless than 50, less than 25, less than 10, or less than 5 gels per ft² of25 micron film. Herein, gels encompass any film defect with a sizegreater than 200 microns.

EXAMPLES

The invention is further illustrated by the following examples, whichare not to be construed in any way as imposing limitations to the scopeof this invention. Various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, maysuggest themselves to one of ordinary skill in the art without departingfrom the spirit of the present invention or the scope of the appendedclaims.

Melt index (MI, g/10 min) can be determined in accordance with ASTMD1238 at 190° C. with a 2,160 gram weight, and high load melt index(HLMI, g/10 min) was determined in accordance with ASTM D1238 at 190° C.with a 21,600 gram weight. Density was determined in grams per cubiccentimeter (g/cm³) on a compression molded sample, cooled at 15° C. perminute, and conditioned for 40 hours at room temperature in accordancewith ASTM D1505 and ASTM D4703.

Dart impact strength (g/mil) was measured in accordance with ASTM D1709(method A, 26 inches, F50). Blown films were produced from the ethylenepolymers on a high density blown film line having a 1.5-in diameterDavis-Standard extruder with a L/D of 24:1, and a 2-in diameter Sano diewith a 35-mil die gap. Processing conditions included barreltemperatures of 210-230° C., a screw speed of 30 rpm, an output rate of17-18 lb/hr, a film thickness of 1 mil, a 4.1 blow-up ratio, a linespeed of 65 ft/min, a frostline height of 14 in, and a layflat width of12.5 in.

Gels were measured on 25 μm (1 mil) film, using an automatedcamera-based gel counting machine made by Optical Control System (OCS),Model FS-5. The system consisted of a light source and a detector. Thefilm was passed through the system, between the light source and thedetector, with a 150-mm (6-inch) inspection width. A total of 10 squaremeters of film area was inspected and the gels with sizes of greaterthan 200 μm were analyzed, and then normalized per square foot of film.

Molecular weights and molecular weight distributions were obtained usinga PL-GPC 220 (Polymer Labs, an Agilent Company) system equipped with aIR4 detector (Polymer Char, Spain) and three Styragel HMW-6E GPC columns(Waters, Mass.) running at 145° C. The flow rate of the mobile phase1,2,4-trichlorobenzene (TCB) containing 0.5 g/L2,6-di-t-butyl-4-methylphenol (BHT) was set at 1 mL/min, and polymersolution concentrations were in the range of 1.0-1.5 mg/mL, depending onthe molecular weight. Sample preparation was conducted at 150° C. fornominally 4 hr with occasional and gentle agitation, before thesolutions were transferred to sample vials for injection. An injectionvolume of 200 μL was used. The integral calibration method was used todeduce molecular weights and molecular weight distributions using aChevron Phillips Chemical Company's HDPE polyethylene resin, MARLEX®BHB5003, as the broad standard. The integral table of the broad standardwas pre-determined in a separate experiment with SEC-MALS. Mn is thenumber-average molecular weight, Mw is the weight-average molecularweight, Mz is the z-average molecular weight, My is viscosity-averagemolecular weight, and Mp is the peak molecular weight (location, inmolecular weight, of the highest point of the molecular weightdistribution curve).

The respective LMW component and HMW component properties weredetermined by deconvoluting the molecular weight distribution (see e.g.,FIG. 6) of each polymer. The relative amounts of the LMW and HMWcomponents (weight percentages) in the polymer were determined using acommercial software program (Systat Software, Inc., PEAK FIT v. 4.05).The other molecular weight parameters for the LMW and HMW components(e.g., Mn, Mw, Mz, etc., of each component) were determined by using thedeconvoluted data from the PEAK FIT program, and applying a PEAK FITChromatography/Log Normal 4-Parameter (Area) Function and two peakswithout any constraints in deconvolution, per below (where a₀=area;a₁=center; a₂=width (>0); and a₃=shape (>0, ≠1)):

$y = {\frac{a_{0}\sqrt{\ln(2)}( {a_{3}^{2} - 1} )}{a_{2}a_{3}{\ln( a_{3} )}\sqrt{\pi}{\exp\lbrack \frac{\ln( a_{3}^{2} )}{4{\ln(2)}} \rbrack}}{\exp\lbrack {- \frac{{\ln(2)}{\ln( {\frac{( {x - a_{1}} )( {a_{3}^{2} - 1} )}{a_{2}a_{3}} + 1} )}^{2}}{{\ln( a_{3} )}^{2}}} \rbrack}}$

Melt rheological characterizations were performed as follows.Small-strain (less than 10%) oscillatory shear measurements wereperformed on an Anton Paar MCR rheometer using parallel-plate geometry.All rheological tests were performed at 190° C. The complex viscosity|η*| versus frequency (ω) data were then curve fitted using the modifiedthree parameter Carreau-Yasuda (CY) empirical model to obtain the zeroshear viscosity—η₀, characteristic viscous relaxation time—τ_(η), andthe breadth parameter—a (CY-a parameter). The simplified Carreau-Yasuda(CY) empirical model is as follows.

${{{\eta*(\omega)}} = \frac{\eta_{0}}{\lbrack {1 + ( {\tau_{\eta}\omega} )^{a}} \rbrack^{{({1 - n})}/a}}},$wherein: |η*(ω)|=magnitude of complex shear viscosity;

-   -   η₀=zero shear viscosity;    -   τ_(η)=viscous relaxation time (Tau(η));    -   a=“breadth” parameter (CY-a parameter);    -   n=fixes the final power law slope, fixed at 2/11; and    -   ω=angular frequency of oscillatory shearing deformation.

Details of the significance and interpretation of the CY model andderived parameters can be found in: C. A. Hieber and H. H. Chiang,Rheol. Acta, 28, 321 (1989); C. A. Hieber and H. H. Chiang, Polym. Eng.Sci., 32, 931 (1992); and R. B. Bird, R. C. Armstrong and O. Hasseger,Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2nd Edition.John Wiley & Sons (1987); each of which is incorporated herein byreference in its entirety. The tan δ at 0.1 sec⁻¹, tan δ at 100 sec⁻¹,viscosity at 0.1 sec⁻¹, and viscosity at 100 sec⁻¹ properties weredetermined using the Carreau-Yasuda (CY) empirical model.

The long chain branches (LCBs) per 1000 total carbon atoms of theoverall polymer can be calculated using the method of Janzen and Colby(J. Mol. Struct., 485/486, 569-584 (1999), incorporated herein byreference in its entirety), from values of zero shear viscosity, η₀(determined from the Carreau-Yasuda model, described hereinabove), andmeasured values of Mw obtained using a Dawn EOS multiangle lightscattering detector (Wyatt).

Metals content, such as the amount of catalyst residue in the ethylenepolymer or film/article, can be determined by ICP analysis on aPerkinElmer Optima 8300 instrument. Polymer samples can be ashed in aThermolyne furnace with sulfuric acid overnight, followed by aciddigestion in a HotBlock with HCl and HNO₃ (3:1 v:v).

Solid activator particle size distributions were determined by using anaqueous suspension of the activator and a Microtrac S3500 laser particlesize analyzer. Conditions were set to “opaque” with a run time of 30sec, number of measurements 3, and shape spherical. As a skilled artisanwould readily recognize, supporting the metallocene compound(s) on thesolid activator would not impact the particle size distribution, thusthe particle size distribution of the supported metallocene catalystwould be effectively the same as the particle size distribution of thesolid activator. Polymer particle size distributions were obtained on adry basis with a Beckman-Coulter, model Fraunhofer RF780F LS 13 320laser-based particle size analyzer. Conditions were set to 0.7%residual, 9.9 inches of water of vacuum, 2% of obscuration, number ofpasses 3, and a 23 sec run time.

Example A Particle Size Distributions of Solid Activators

Solid activators were prepared as follows. A silica-coated aluminahaving a surface area of 450 m²/g, a pore volume of 1.3 mL/g, and 38 wt.% silica was treated in three ways. In the first method, 1 part of thesilica-coated alumina by weight was slurried in 5.7 parts by weight ofwater. Then, 0.055 parts by weight of hydrofluoric acid were added, andthe slurry was stirred for several hours. During this time, fluorine wasgradually adsorbed, and when this was complete, the fluoridedsilica-coated alumina was spray dried, producing a solid activator withan average particle size of 48 μm. This material was then given afurther treatment using an air-mill, also called a jet-mil, which brokedown the largest particles into many smaller ones. This produced theComparative 1 solid activator, with a d50 average particle size(diameter) of 9.4 μm.

In the second method, the same procedure was used, however, rather thanbeing subjected to jet-milling, the solid activator was instead passedthrough a 270 mesh sieve. That which remained on the screen wasrecycled, whereas that which passed through the screen was captured foruse later, producing the Inventive 2 solid activator, with a d50 averageparticle size of 31.6 μm.

In the third method, one part by weight of the same silica-coatedalumina was slurried in 4.8 parts by weight of water, then 0.058 partsof tetrafluoroboric acid and 0.048 parts of zinc oxide powder wereadded. After slurrying for several hours and spray drying, this materialwas further refined using air classification to remove the largestparticles. Then, in a second but similar step, this solid activator wasfurther air-classified to remove the smallest particles, resulting inthe Inventive 1 solid activator, having a d50 average particle size of19.3 μm.

In a fourth method, an alumina having a surface area of 300 m/g and apore volume of 1.3 mL/g was calcined at 600° C. Then, one part by weightof this material was slurried in 5.2 parts by weight of water, followingby adding 0.15 parts of sulfuric acid. After slurrying for another 30min and spray drying, this procedure produced the Comparative 2 solidactivator, having a d50 average particle size of 86.5 μm.

FIG. 1 illustrates the particle size distributions of these four solidactivators (amount of particles by weight versus the particle diameterplotted on a log-scale). Table I summarizes various parameterscalculated from the particle size distributions of the four solidactivators: Inventive 1, Inventive 2, Comparative 1, and Comparative 2.The Inventive 1 solid activator had the narrowest particle sizedistribution and a d50 average particle diameter larger than that ofComparative 1 and smaller than that of Inventive 2 and Comparative 2.

The d50 average particle size of the Inventive 1 solid activator was19.3 μm and the particle size span ((d90−d10)/d50) was less than 1(0.85). The Inventive 1 solid activator also had a d10 particle sizegreater than 10 μm (12.7 μm), a d95 particle size less than 40 μm (˜34μm), and a ratio of d90/d10 less than 3 (2.3). Further, less than 2% ofthe Inventive 1 solid activator had a particle size of less than 10 μm,less than 1% had a particle size of greater than 45 μm, and at least 99%had a particle size of less than 50 μm.

The d50 average particle size of the Inventive 2 solid activator was31.6 μm and the particle size span ((d90−d10)/d50) was less than 1.5(1.23). The Inventive 2 solid activator also had a d10 particle sizegreater than 10 μm (11.2 μm), a d95 particle size less than 60 μm (˜57μm), and a ratio of d90/d10 less than 5 (4.5). Further, less than 5% ofthe Inventive 2 solid activator had a particle size of less than 10 μm,less than 20% had a particle size of greater than 45 μm, and at least88% had a particle size of less than 50 μm.

Example B Particle Size Distributions of the Resultant Polymer Powders

The four solid activators of Example A were then calcined at 600° C. indry air for eight hours, and afterward stored under nitrogen until use.Each was tested in a commercial-scale loop reactor, using twometallocenes simultaneously to produce a nominal 7-9 HLMIethylene/l-hexene copolymer with a nominal 0.948-0.950 density. The twometallocenes used are shown below. During these experiments, theethylene concentration was 4-6 wt. %, the reactor temperature was 205°F., and the residence time was 50-75 min. The feed rate of hydrogen andeach metallocene were varied to achieve the target HLMI and density andthis was accomplished with a weight-to-weight feed ratio of MET 2 to MET1 of 2.1-3.5 and a hydrogen feed rate of 0.15-0.3 lb H₂/1000 lbethylene. Reactant concentrations in the precontactor were 30,000-50,000ppm solid activator and 5000-6000 ppm triisobutylaluminum, the totalmetallocene to solid activator weight ratio was 0.6-0.7%, thetriisobutylaluminum to solid activator weight ratio was 0.12 to 0.19,and the residence time was 30 min.

Particle size distributions of the polymers were obtained and are shownin FIG. 2, while Table II list various parameters determined from thedistributions in FIG. 2. In Table II, the d50 average particle size ofthe Inventive 1 polymer powder was 235 μm and the particle size span((d90−d10)/d50) was less than 1.5 (1.3). The Inventive 1 polymer powderalso had a d90 particle size less than 500 μm (462 μm) and a ratio ofd90/d10 less than 4 (3.1). Further, less than 3% (2.2%) of the Inventive1 polymer powder had a particle size of less than 100 μm and less than1% had a particle size of greater than 1000 μm.

The d50 average particle size of the Inventive 2 polymer powder was 388μm and the particle size span ((d90−d10)/d50) was less than 1.5 (1.37).The Inventive 2 polymer powder also had a d90 particle size less than700 μm (694 μm) and a ratio of d90/d10 less than 5 (4.2). Further, lessthan 5% (3.4%) of the Inventive 2 polymer powder had a particle size ofless than 100 μm and less than 1% had a particle size of greater than1000 μm.

In slurry polymerization, one catalyst particle tends to make onemuch-larger polymer particle, unless it is broken by extreme mechanicalforces. Thus, the shape of the polymer particles, and also the polymerparticle size distribution, tend to replicate that of the catalystparticle. Thus, due to the small average particle diameter of theComparative 1 solid activator, and the large percentage of particlesless than 10 μm (fines), Comparative 1 resulted in severe transferproblems during operations with both activator/catalyst and theresultant polymer. In fact, the problem was so severe that the test hadto be stopped due to unmanageable plugging of a downstream polymer feedhopper. Consequently, the Comparative 1 solid activator was deemedcompletely unsuitable for commercial loop slurry polymerization.

The Inventive 2 solid activator was found to be acceptable duringcalcination operations, because it caused no transfer difficultiesduring charging and discharging operations of the calciner. Neither didit cause difficulties during the charging operation to the reactor feedtank. However, the polymer made still exhibited some minor difficultieswith transfer of the polymer powder in downstream drying and transferoperations. Several plugs were obtained during the test, however, thetransfer problems were manageable and the test run continuedsuccessfully to the end.

In contrast, the Inventive 1 solid activator/catalyst performedexceptionally well during the loop slurry polymerization experiments,transferring easily and cleanly during calcination and then to thereactor. The charging and discharging operations offered very littleresistance from packing or static. Likewise, Inventive 1 made polymerpowder that was also exceptional in its transfer properties during thetest. It discharged from the reactor easily, with no plugs or fines ordust, and it performed well during downstream purging/drying operations.Transfer to the storage and later to the pelletizing silos wentextremely well, indicating that the smaller particle size offers lessresistance and has less tendency to “drop out” and pack.

The Comparative 2 solid activator/catalyst had a moderately narrow sizedistribution, but with much larger diameters than the other examples.This catalyst produced large polymer particles, which are more prone tobreakage, which can be seen in FIG. 2 by the increased breadth of thepolymer particle size distribution, compared to that of theactivator/catalyst particle size distribution (FIG. 1). Note that thepolymer has more small particles than would be expected from the largenarrow catalyst particle size distribution. Thus, despite the largeroverall size, Comparative 2 produced more polymer fines than either ofthe smaller Inventive examples.

The higher amount of polymer fines produced by Comparative 2 due tobreakage also resulted in transfer difficulties downstream, despite theoverall larger average size. The larger particles also caused problemsin the reactor itself, because they have more difficulty circulatingaround the loop. This is because large particles tend to have higherterminal velocity, and thus they have a greater tendency to “drop out”or fall. Because the circulation pump must work against this tendency,it usually requires higher amperage to circulate the larger particlesand the pump reaches its limit more quickly. This tends to limit theconcentration of polymer in the slurry, and thus ultimately, the finalproduction rate.

In contrast, the Inventive 1 solid activator/catalyst performedexceptionally in the loop reactor. Because the PE particles made weresmaller, their terminal velocity in isobutane was lower, compared toInventive 2 and especially the larger particles of Comparative 2. Thisresulted in the pump amperage dropping significantly in comparison. Thedrop in required pump power allows more concentrated slurries to beused, which increases production rate. The catalyst from Inventive 1also produced little to no polymer fines, such as particles smaller that100 μm, or smaller than 75 m, or smaller than 50 μm. This is because itis usually the larger particles breaking up that produce fines, and theinventive catalysts had few or no larger particles. This also helpsproduction rates, because fines can cause localized over-heating(“hot-spots”) or fouling or plate-out as they stick to walls andthermocouples by static and continue to polymerize ethylene to build up“wall scale” that inhibits flow and heat transfer. Thus, Inventive 1represented the best reactor performance, with respect to particle sizedistribution of both the activator/catalyst and the resultant polymer.

Another important polymer attribute for loop slurry polymerization isthe concept of “gels.” The term is used to indicate visual and surfaceimperfections in the final polymer article, most especially filmproducts. Such imperfections or “gels” in the film not only detract fromthe appearance of the article (such as a bag), but the resulting bumpson the surface also can cause printing defects. Gels can have manysources, including contamination from dirt or other foreign material,additive particles that are insufficiently blended into the moltenpolymer during pelletizing extrusion, unreacted catalyst particles, orother polymer particles left from previous production of other polymergrades of higher molecular weight or from other sources that were notsuccessfully blended into the bulk polymer during pelletizing extrusion.

Large catalyst particles, and the resulting large polymer particles,also tend to make larger, more noticeable gels, resulting in an inferiorfinal product. The influence of catalyst/polymer particle size on gelcount is illustrated in FIG. 3. The graph represents a transition fromone solid activator/catalyst to another solid activator/catalyst. Asolid activator similar to Comparative 2 was used to produce thepolymer. The gel content was being measured about every three hours asthe polymer was made. Due to the long residence time of the overallsystem, it took almost a day to fully replace one catalyst with theother. On this occasion, the gel count was initially near 1000 gels(>200 μm) per square foot of film. At a time of about 32 hr, the feedingof Comparative 2 was stopped and the feeding of Inventive 1 was begun,although no other changes were made to the reactor. Immediately, the gelcount started dropping as the first activator/catalyst, and its largerpolymer particles, were gradually replaced by the Inventive 1activator/catalyst and the smaller polymer particles it makes. Thischanged caused the gel count to drop by almost two orders of magnitude,to less than 50 gels/ft and decreasing before the experiment wascompleted.

Another problem that can result from the production of a broad sizedistribution of polymer particles is segregation between the sizesduring handling. This is especially a problem when the polymer particlesof different sizes also have different molecular weights and differentdensities. This can happen from many causes, such as development offeedstock diffusion gradients through the individual particles duringproduction, non-uniform adsorption of various catalyst componentsincluding the aluminum alkyl, selective breakage, etc. FIG. 4 shows anexample of this effect. Three polymers were fluidized by nitrogen for ashort time in a special test designed to measure the tendency of powdersto segregate (ASTM 6941). When the fluidization was stopped, the stillpolymer bed was then sampled from the top, bottom, and middle positions.FIG. 4 shows the particle size distributions of one of these polymers,made with the Comparative 2 solid activator, in comparison to theoriginal unfluidized composite sample. The Comparative 2 polymer had astrong tendency to segregate, with small particles preferring to rise tothe top of the bed and large particles preferring to sink to the bottom.This not only contributes to flow problems and feeder “surging,” but thesmaller particles were also found to have significantly lower molecularweight than the larger particles, so that the polymer molecular weightexiting the pelletizing extruder can vary over time due to particlesettling upstream, causing the pellet HLMI to vary even within the samelot of polymer powder.

In contrast, the Inventive 1 polymer powder exhibited little or notendency to segregate. The results of these segregation tests aresummarized in Table III, where the Inventive 1 polymer is compared totwo different polymers made with the Comparative 2 activator/catalyst.The difference between top and bottom of the bed indicates the degree ofseparation. The percent change is the difference in size between top andbottom divided by that of the composite. The coefficient of variation isthe standard deviation of the three numbers (top, bottom, composite)divided by the average of the three numbers. Surprisingly, all of thecoefficient of variation values at d10, d50, and d90 are significantlylower for the Inventive 1 polymer compared to that of Comparative 2.

When a comonomer, such as 1-hexene, is introduced into the reactor, itincorporates into the polymer, making the polymer less crystalline, andtherefore with a lower density. Larger particles tend to incorporate adifferent amount of comonomer from that incorporated by the smallerparticles, resulting in different densities. This is particularlyproblematic in dual metallocene catalyst systems. The phenomenon can becaused by feedstock diffusion gradients generated through the particles,or by non-uniform composition of catalyst particles, or even throughreactor gradients such as the “hot-spots” described above. The degree ofheterogeneity in the polymer powder can thus be quantified by aflotation test. That is, polymer powder was slurried in isopropanol,which has a lower density than any polymer particle. Therefore, all ofthe particles sink in the alcohol. However, small increments of waterwere then added to the slurry to raise the liquid density in smallincrements. As water was slowly added, particles having the lowestdensity begin to float and they were skimmed off the top, and dried.More water was then added and more polymer particles rise to the top andthe process is repeated. Eventually, the density of the liquid wasincreased enough so that all of the polymer particles, even those withthe least comonomer incorporated, rise to the top and were skimmed off.In this way, the entire polymer powder was fractionated by particledensity and the amount of comonomer each particle incorporated.

An example of the flotation test is shown in FIG. 5. The amount offloating polymer is plotted against the density of the liquid for eachincrement of water added for the Inventive 1 polymer powder, theInventive 2 polymer powder, and Comparative 2 polymer powder. The twoinventive polymers had a much narrower spread in the density of thepolymer particles made, indicating significantly better homogeneitywithin the powder. The density of the polymer particles in Comparative 2varied from 0.955 to 0.915, for a density spread of 0.04 g/cm³. Incontrast, the density spreads for the two inventive polymers were only0.003-0.005 g/cm³.

Examples 1-40 Polymer Properties

Pilot scale polymerizations were conducted using a 30-gallon slurry loopreactor at a production rate of 30-33 pounds of polymer per hour.Polymerizations were carried out under continuous particle form processconditions in a loop reactor (also referred to as a slurry process) bycontacting a dual metallocene solution in toluene and isobutane andpossibly 1-hexene, an organoaluminum solution (triisobutylaluminum,TIBA), and a solid activator in a 1-L stirred autoclave with continuousoutput to the loop reactor. The TIBA and dual metallocene solutions werefed as separate streams into the isobutane flush going into theautoclave. The solid activator was also continuously flushed into theautoclave with isobutane and the TIBA/metallocene mixture flowingtogether to the autoclave. The isobutane flush used to transport thesolid activator into the autoclave was set at a rate that would resultin a residence time of 30 minutes in the autoclave. The total flow fromthe autoclave then entered the loop reactor.

The ethylene used was polymerization grade ethylene obtained from AirGasor Praxair which was then further purified through a column ofalumina-zeolite adsorbent (dehydrated at 230-290° C. in nitrogen).Polymerization grade 1-hexene (obtained from Chevron Phillips ChemicalCompany) was used and was further purified by distillation and passedthrough a column of alumina-zeolite absorbent dehydrated at 230-290° C.in nitrogen. The loop reactor was liquid full, 15.2 cm in diameter, andhad a volume of 30 gallons (113.6 liters). Liquid isobutane was used asthe diluent. Hydrogen was added to tune the molecular weight and/or HLMIof the polymer product. The isobutane used was polymerization gradeisobutane (obtained from Enterprise) that was further purified bydistillation and subsequently being passed through a column of alumina(dehydrated at 230-290° C. in nitrogen). Co-catalyst TIBA was added in aconcentration in 30 to 90 ppm based on the weight of the diluent in thepolymerization reactor.

Reactor conditions included a reactor pressure of 600 psig, a mol %ethylene of 4-7 wt % (based on isobutane diluent), a 1-hexene content of0.4-0.8 mol % (based on isobutane diluent), 0.5-0.8 lb of hydrogen per1000 lb of ethylene, and a polymerization temperature of 88-98° C. Thereactor was operated to have a residence time of 75 min. Totalmetallocene concentrations in the reactor were within a range of 1 to 3parts per million (ppm) by weight of the diluent. The solid activatorwas fed to the reactor at the rate of 4-9 g per hour.

Polymer was removed from the reactor at the rate of 30-33 lb/hr andpassed through a flash chamber and a purge column. Nitrogen was fed tothe purge column to ensure the powder/fluff was hydrocarbon free. Thestructures for metallocenes MET 1 and MET 2 that were used in thecatalyst system are shown below (the weight ratio of MET 1:MET 2 was inthe 0.3:1 to 1.5:1 range to produce the desired polymer composition):

The particle size distributions of the polymer powder/fluff producedusing this dual catalyst system containing the solid activatorsInventive 1, Inventive 2, Comparative 1, and Comparative 2 aresummarized in FIG. 2 and Table II. Polymer particle size distributionsfrom the pilot plant experiments were very similar to those describedabove. The polymer powder made using the Inventive 1 solid activator hadthe narrowest particle size distribution, followed by Inventive 2,Comparative 1, and finally Comparative 2.

The following data tables contain polymers from both the commercialreactor (Example 1-15) and the pilot plant (Examples 16-40), all madeusing solid activators Inventive 1, Inventive 2, or Comparative 2. TheComparative 1 solid activator performed so poorly in the loop reactorthat no useable polymer could be collected to analyze. In each examplebelow, the resulting polymer powder was mixed and pelletized using aconventional pelletizing extruder to form resin pellets. Then, for someexamples, 1-mil blown films were produced for dart impact testing.

Table IV lists the solid activator used to make each polymer, as well asthe resultant density, HLMI, and puncture resistance (dart impactstrength) of 1-mil film blown for each polymer. FIG. 6 illustrates thebimodal molecular weight distributions (amount of polymer versus thelogarithm of molecular weight) of the polymers of Examples 1, 4, 12, 18,21, and 36. The polymers of Examples 1-15 had densities ranging from0.947 to 0.95 g/cm³, HLMI values ranging from 5 to 8 g/10 min, and dartimpact values averaging 390 g/mil, unexpectedly higher than the averagedart impact of 320 g/mil for Examples 16-40. While not wishing to bebound by theory, it is believed that the improved homogeneity ofcomonomer incorporation and polymer powder/fluff density (e.g., FIG. 5)results in the improvement in dart impact strength, even though theoverall bulk polymer densities are unchanged.

Table V summarizes certain molecular weight characteristics of thepolymers of Examples 1-40. The Mw values ranged from 250,000 to 320,000g/mol and the ratios of Mw/Mn ranged from 21 to 42 for the polymers ofExample 1-15, whereas the Mw values were below 250,000 g/mol and theMw/Mn values were below 20 for many of Examples 16-40.

The bimodal molecular weight distributions from each of these polymerswere then deconvoluted into their respective high-MW and low-MWcomponents (LMW and HMW) as described herein. The molecular weightparameters for the LMW and HMW components (e.g., Mn, Mw, and Mz of eachcomponent) of each example were determined by using the deconvoluteddata from the PEAK FIT program, and are listed in Tables VI and Vil. Asshown in these tables, the ethylene polymers of Examples 1-15 contained60-67 wt. % of the LMW component, which had a Mw of 32,000-40,000 g/moland a ratio of Mz/Mw from 2.3 to 3. The HMW component had a Mn rangingfrom 290,000 to 400,000 g/mol. The combined polymer properties ofExamples 1-15 are not found in any of Examples 16-40.

Table VIII summarizes certain rheological characteristics at 190° C. forthe polymers of Examples 1-40. These were determined using theCarreau-Yasuda model as described above. The polymers of Examples 1-15had CY-a parameters of 0.49-0.62, relaxation times (τ(η)) from 1.5 to 4sec, viscosities at 100 sec⁻¹ (η @100) from 2100 to 3500 Pa-sec, andratios of the viscosity at 0.1 sec⁻¹ to the viscosity at 100 sec⁻¹ (η @0.1/η @ 100) ranging from 41 to 68.

In summary, these polymer properties demonstrate the unexpectedrelationship between the particle size distribution of the solidactivators (or the supported metallocene catalysts) and the polymerrheology and molecular weight distribution, particularly as it pertainsto the LMW and the HMW components.

TABLE I Particle size distributions of solid activators. InventiveInventive Comparative Comparative Example 1 2 1 2 Mv, μm 20.22 30.411.53 92.63 Mn, μm 5.63 6.29 3.01 40.43 Mv/Mn 3.59 4.83 3.83 2.29 Mp, μm20.17 33.0 13.08 88.00 Std Dev, μm 5.97 14.41 7.23 35 .07 Mp-Mv, μm 0.2%7.9% 1.55 5.3% Mv/Mp 1.00 0.92 0.88 1.05 Ma, μm 16.37 21.82 6.90 74.74Mp/Ma 1.23 1.51 1.90 1.18 Mp/Ma, μm 3.80 11.18 6.18 13.26 Full Breadth,μm 49.93 112.2 86.84 368.34 ½ ht Breadth, μm 12.76 39.14 21.56 73.47Weight Percentile, μm 10% 12.74 11.23 3.39 47.47 20% 15.06 19.45 4.6061.77 30% 16.59 24.58 5.91 70.46 40% 17.95 28.30 7.49 78.53 50% 19.3131.58 9.36 86.48 60% 20.79 34.81 11.47 95.1 70% 22.55 38.41 13.88 105.380% 24.94 42.94 16.95 119.1 90% 29.15 50.19 22.09 142.9 95% 33.77 57.6427.81 168.7 90/10 2.29 4.47 6.52 3.01 90-10, μm 16.41 38.96 18.70 95.4380/20 1.66 2.21 3.68 1.93 80-20, μm 9.88 23.49 12.35 57.33 95-10, μm21.03 46.41 24.42 121.23 95-50, μm 14.46 26.06 18.45 82.22 50-10, μm6.57 20.35 5.97 39.01 Span, (D90-D10)/ 0.85 1.23 2.00 1.10 D50 Less than10 μm, % 1.3 4.9 49.4 0.0 At least 45 μm, % 0.9 16.4 1.0 91.7 Less than50 μm, % 99.1 88.8 99.0 10.3

TABLE II Particle size distributions of PE powder made using four solidactivators. Inventive Inventive Comparative Comparative Solid Activator1 2 1 2 Mv, μm 277.0 410.9 94.2 895.6 Median, μm 235.4 387.7 79.2 803.6Mean/Median 1.18 1.06 1.19 1.11 Mode, μm 223.4 471.1 37.5 1091 Std.Dev., μm 156.4 205.3 82.8 524.1 Coeff. Of Variation 56% 50% 88% 62% Fullwidth, μm 430.2 998.0 326.0 2480.0 Weight Percentile, μm 10% 150.9 163.527.1 138.7 25% 186.7 255.9 45.2 436.1 50% 235.4 387.7 78.0 803.6 75%306.3 539.9 118.2 1231 90% 462.0 694.4 162.2 1622 Weight Percentile, %   <1 μm 0.0% 0.0% 0.0% 0%    <5 μm 0.0% 0.0% 0.2% 0.0%   <10 μm 0.1%0.1% 1.0% 0.2%   <50 μm 0.7% 1.1% 28.8% 3.2%  <100 μm 2.2% 3.4% 65.0%7.3%  <200 μm 31.8% 15.5% 95.6% 13.7% <1000 μm 99.6% 99.3% 100.0% 62.8%Weight % on sieve # 1000 1.1% 2.6% 47.8% 5.3% 200 12.2% 7.6% 39.1% 5.4%100 46.2% 17.3% 11.2% 5.4% 60 28.0% 35.9% 0.8% 8.3% 40 11.1% 35.1% 1.1%28.8% 20 1.3% 1.7% 0.0% 39.1% 12 0.0% 0.0% 0.0% 7.7% thru 100 mesh 13.3%10.1% 86.9% 10.7% thru 200 mesh 1.1% 2.6% 47.8% 5.3% Span, 1.32 1.371.73 1.85 (D90-D10)/D50

TABLE III Polymer powder segregation test results. Catalyst Sample d10,μm d50, μm d90, μm Mean, μm Comparative 2 Top 241 737 1409 787Comparative 2 Middle 340 807 1522 868 Comparative 2 Bottom 439 880 1490921 Comparative 2 Composite 353 830 1549 889 Comparative 2 Change 56.2%17.1% 5.3% 15.1% Comparative 2 Coeff of Var. 29.1% 8.8% 4.0% 7.9%Comparative 2 Top 176 554 1056 590 Comparative 2 Middle 367 704 1178 738Comparative 2 Bottom 415 782 1290 816 Comparative 2 Composite 339 7161230 748 Comparative 2 Change 70.6% 31.7% 19.0% 30.1% Comparative 2Coeff of Var. 39.6% 17.0% 10.0% 16.0% Inventive 1 Top 143 228 453 228Inventive 1 Middle 154 238 457 238 Inventive 1 Bottom 158 237 467 237Inventive 1 Composite 151 235 462 235 Inventive 1 Change 10.0% 3.5% 3.0%3.5% Inventive 1 Coeff of Var. 5.1% 2.2% 1.5% 2.2%

TABLE IV Summary of polymer examples produced using solid activators.Density HLMI Dart Impact Example Solid Activator (g/cc) (g/10 min)(g/mil) 1 Inventive 1 0.9478 6.1 — 2 Inventive 2 0.9486 6.9 378 3Inventive 1 0.9487 8.0 — 4 Inventive 1 0.9485 7.6 — 5 Inventive 1 0.94866.5 — 6 Inventive 1 0.9488 5.6 — 7 Inventive 2 0.9493 5.5 462 8Inventive 2 0.9482 6.4 316 9 Inventive 2 0.9485 6.7 422 10 Inventive 20.9488 6.3 524 11 Inventive 2 0.9486 6.5 350 12 Inventive 2 0.9484 6.1292 13 Inventive 2 0.9485 6.0 448 14 Inventive 2 0.9481 5.1 398 15Inventive 2 0.9480 5.8 342 16 Comparative 2 0.9495 6.7 150 17Comparative 2 0.9501 7.2 158 18 Comparative 2 0.9471 5.7 131 19Comparative 2 0.9478 6.3 220 20 Comparative 2 0.9503 6.1 195 21Comparative 2 0.9419 6.4 481 22 Comparative 2 0.9409 5.3 371 23Comparative 2 0.9545 7.6 189 24 Comparative 2 0.9464 13.0 311 25Comparative 2 0.9431 3.4 409 26 Comparative 2 0.9495 12.1 — 27Comparative 2 0.9491 22.0 217 28 Comparative 2 0.9448 5.4 590 29Comparative 2 0.9453 5.4 592 30 Comparative 2 0.9482 11.3 499 31Comparative 2 0.9479 11.8 360 32 Comparative 2 0.9481 10.7 — 33Comparative 2 0.9493 6.4 399 34 Comparative 2 0.9579 6.0 366 35Comparative 2 0.9513 41.5 189 36 Comparative 2 0.9529 8.0 — 37Comparative 2 0.9574 23.1 — 38 Comparative 2 0.9578 19.5 — 39Comparative 2 0.9535 8.4 — 40 Comparative 2 0.9537 7.0 —

TABLE V Molecular Weight Characterization (g/mol) Example Mn/1000Mw/1000 Mz/1000 Mv/1000 Mp/1000 Mw/Mn Mz/Mw 1 8.6 287 1339 206 24 33.24.67 2 8.1 287 1331 205 24 35.4 4.63 3 7.5 310 1399 223 22 41.6 4.51 48.5 298 1302 215 23 35.1 4.37 5 9.3 312 1338 227 24 33.4 4.29 6 8.1 2621271 186 24 32.6 4.84 7 9.6 279 1119 204 20 29.1 4.01 8 9.0 251 1028 18622 28.0 4.09 9 12.0 273 1053 203 24 22.8 3.86 10 12.1 278 1079 207 2522.9 3.88 11 13.0 277 1085 207 516 21.3 3.92 12 12.3 282 1112 210 52323.0 3.94 13 11.9 269 1060 201 490 22.7 3.94 14 12.7 291 1140 217 52323.0 3.91 15 13.1 287 1121 214 530 21.9 3.90 16 12.6 311 1376 227 3424.6 4.42 17 15.9 314 1455 229 40 19.8 4.63 18 22.6 397 2001 285 68 17.65.05 19 38.2 438 2632 308 81 11.5 6.01 20 10.2 282 1275 207 29 27.8 4.5121 8.6 182 506 147 239 21.1 2.78 22 6.5 183 494 148 258 28.1 2.70 23 6.4182 549 143 258 28.5 3.02 24 5.5 182 593 140 328 33.2 3.26 25 8.5 259868 200 420 30.5 3.35 26 6.2 188 767 138 388 30.6 4.07 27 5.6 172 683126 349 30.6 3.97 28 8.8 254 877 207 436 28.8 3.45 29 10.1 263 869 200483 26.1 3.30 30 8.9 256 1016 187 19 28.9 3.96 31 8.3 251 1233 179 1930.2 4.92 32 8.1 242 961 177 17 29.8 3.97 33 8.9 268 1027 199 479 30.23.83 34 9.5 268 1085 197 472 28.3 4.05 35 7.6 221 1041 155 18 29.1 4.7136 10.1 192 752 162 353 19.1 3.91 37 10.5 178 709 133 17 17.0 3.97 3810.7 181 712 136 16 16.9 3.93 39 10.6 195 678 139 351 18.3 3.48 40 10.7200 689 144 333 18.6 3.45

TABLE VI Molecular Weight Characterization (g/mol) - Low molecularweight component Example Mn/1000 Mw/1000 Mz/1000 Mw/Mn Mz/Mw Wt. % 1 7.639.2 108 5.15 2.76 66.9 2 7.2 37.6 107 5.21 2.85 62.6 3 5.8 34.5 92 5.902.66 62.4 4 6.2 34.4 91 5.52 2.65 62.2 5 6.5 36.4 101 5.58 2.77 60.8 66.2 34.8 89 5.64 2.56 67.0 7 6.4 32.5 96 5.11 2.94 62.6 8 6.2 32.4 805.20 2.46 60.5 9 8.2 38.9 101 4.76 2.58 62.7 10 8.2 39.1 101 4.75 2.5962.7 11 8.2 35.0 83 4.28 2.37 60.3 12 8.2 39.4 104 4.80 2.63 62.4 13 7.736.1 93 4.67 2.58 61.4 14 8.2 38.4 99 4.67 2.59 61.3 15 8.4 38.0 97 4.512.55 61.6 16 8.7 43.9 105 5.07 2.38 65.7 17 11.2 50.3 109 4.49 2.17 68.718 18.4 71.4 135 3.87 1.90 71.5 19 29.7 89.4 163 3.00 1.82 73.5 20 6.532.1 71 4.96 2.20 60.8 21 1.9 8.3 18 4.32 2.21 32.5 22 2.2 9.8 23 8.252.32 34.4 23 2.2 9.7 24 6.42 2.43 37.3 24 2.6 11.1 26 5.13 2.31 43.8 255.7 31.2 110 4.59 3.51 53.1 26 3.4 14.7 38 5.89 2.59 53.8 27 3.3 16.5 455.89 2.75 57.0 28 4.8 22.1 54 5.18 2.44 51.4 29 5.5 22.3 53 4.67 2.4052.5 30 6.1 28.8 79 4.38 2.75 63.7 31 5.8 27.9 67 5.28 2.40 64.6 32 5.426.4 67 4.24 2.52 62.9 33 5.5 26.7 72 4.76 2.69 57.3 34 5.6 27.4 75 4.642.73 59.0 35 6.0 28.5 72 4.42 2.54 69.8 36 7.1 28.9 77 4.09 2.67 56.3 376.8 23.9 56 3.50 2.35 61.5 38 6.7 23.0 54 3.45 2.34 59.5 39 6.0 21.0 493.48 2.35 53.6 40 5.5 19.5 48 3.52 2.45 50.5

TABLE VII Molecular Weight Characterization (g/mol) - High molecularweight component Example Mn/100 Mw/1000 Mz/1000 Mw/Mn Mz/Mw 1 381 7701392 2.02 1.81 2 329 666 1208 2.03 1.81 3 359 767 1452 2.14 1.89 4 342743 1383 2.17 1.86 5 353 761 1468 2.16 1.93 6 335 744 1407 2.22 1.89 7378 728 1311 1.92 1.80 8 296 596 1074 2.02 1.80 9 385 681 1138 1.77 1.6710 394 694 1164 1.76 1.68 11 351 662 1150 1.88 1.74 12 395 701 1199 1.781.71 13 363 650 1116 1.79 1.72 14 393 704 1211 1.79 1.72 15 392 701 12021.79 1.71 16 473 832 1487 1.76 1.79 17 522 924 1684 1.77 1.82 18 6191280 2471 2.07 1.93 19 368 1456 3213 3.95 2.21 20 307 639 1105 2.08 1.7321 90 266 472 2.97 1.77 22 110 301 523 2.73 1.74 23 98 301 551 3.06 1.8324 99 315 562 3.19 1.78 25 338 576 926 1.71 1.61 26 124 384 702 3.101.83 27 178 408 687 2.30 1.68 28 264 525 856 1.99 1.63 29 237 530 8582.24 1.62 30 391 668 1073 1.71 1.61 31 358 650 1145 1.81 1.76 32 342 6181009 1.81 1.63 33 310 594 999 1.92 1.68 34 327 615 1043 1.88 1.70 35 398705 1145 1.77 1.63 36 234 433 690 1.85 1.59 37 223 425 705 1.91 1.66 38213 411 682 1.93 1.66 39 204 396 661 1.95 1.67 40 190 375 635 1.98 1.69

TABLE VIII Rheological Characterization at 190° C. Zero shear Tau(η)CY-a η @ 0.1 Tan d @ 0.1 η @ 100 Tan d @ 100 η @ 0.1/ Example (Pa-sec)(sec) parameter (Pa-sec) (degrees) (Pa-sec) (degrees) η @ 100 1 282,4003.53 0.531 140,200 1.97 2172 0.354 64.5 2 220,800 2.01 0.534 128,4002.48 2635 0.373 48.7 3 373,800 3.42 0.582 204,500 2.08 3016 0.340 67.8 4363,700 3.40 0.580 198,800 2.08 2948 0.340 67.4 5 402,800 3.19 0.574222,100 2.13 3423 0.344 64.9 6 295,600 3.61 0.538 147,900 1.97 22460.351 65.9 7 266,500 2.58 0.620 166,000 2.45 2721 0.337 61.0 8 197,8001.63 0.491 111,500 2.55 2692 0.403 41.4 9 251,000 2.37 0.525 137,8002.30 2628 0.370 52.4 10 261,100 2.44 0.539 145,900 2.31 2693 0.364 54.211 261,900 2.40 0.536 146,000 2.31 2728 0.365 53.5 12 264,200 2.30 0.536149,000 2.35 2849 0.367 52.3 13 223,700 2.15 0.537 128,600 2.43 25470.369 50.5 14 273,400 2.30 0.547 157,400 2.39 2971 0.363 53.0 15 264,8002.35 0.544 150,600 2.35 2818 0.363 53.4 16 356,900 3.84 0.565 1836001.96 2611 0.341 70.3 17 469,800 5.48 0.535 204100 1.67 2564 0.341 79.618 4,167,000 63.37 0.307 277100 0.93 2707 0.385 102.4 19 — — 0.048232800 0.71 2964 0.603 78.5 20 239,900 2.38 0.563 140500 2.39 2556 0.35655.0 21 33,940 0.16 0.600 30,410 10.01 2757 0.533 11.0 22 49,650 0.200.575 42,970 8.02 3343 0.519 12.9 23 42,850 0.19 0.539 36,160 7.31 28970.551 12.5 24 47,760 0.32 0.525 37,720 5.48 2235 0.503 16.9 25 230,9001.67 0.602 154,900 2.95 3292 0.356 47.1 26 43,610 0.40 0.543 34,230 5.181756 0.468 19.5 27 51,990 0.50 0.553 40,180 4.80 1806 0.444 22.2 28208,600 1.50 0.601 143,000 3.11 3247 0.361 44.0 29 210,100 1.68 0.596139,900 2.92 2986 0.358 46.9 30 200,100 2.43 0.600 123,100 2.47 21280.344 57.8 31 214,200 2.61 0.613 131,700 2.42 2161 0.339 60.9 32 176,8002.16 0.581 108,900 2.55 2049 0.354 53.1 33 199,000 1.64 0.532 121,0002.70 2784 0.383 43.5 34 197,000 1.85 0.570 123,700 2.69 2561 0.363 48.335 158,700 2.88 0.573 89,770 2.22 1460 0.347 61.5 36 69,890 0.50 0.51950,570 4.28 2540 0.503 19.9 37 55,410 0.51 0.471 37,830 3.86 1728 0.49621.9 38 57,770 0.49 0.469 39,600 3.91 1853 0.501 21.4 39 71,170 0.470.492 39,600 3.91 1853 0.501 21.4 40 70,570 0.43 0.483 50,570 4.28 25400.503 19.9

The invention is described above with reference to numerous aspects andspecific examples. Many variations will suggest themselves to thoseskilled in the art in light of the above detailed description. All suchobvious variations are within the full intended scope of the appendedclaims. Other aspects of the invention can include, but are not limitedto, the following (aspects are described as “comprising” but,alternatively, can “consist essentially of” or “consist of”):

Aspect 1. A catalyst composition comprising a metallocene compound; asolid activator; and optionally, a co-catalyst; wherein the solidactivator (or the supported metallocene catalyst) has a d50 averageparticle size in a range from 15 to 50 μm; and a particle size span((d90−d10)/d50) in a range from 0.5 to 1.5.

Aspect 2. The composition defined in aspect 1, wherein the d50 averageparticle size is in any range disclosed herein, e.g., from 15 to 40 μm,from 15 to 25 μm, from 20 to 30 μm, from 17 to 40 μm, from 17 to 27 μm,or from 17 to 25 μm.

Aspect 3. The composition defined in aspect 1 or 2, wherein the span((d90-d10)/d50) is an any range disclosed herein, e.g., from 0.5 to 1.2,from 0.6 to 1.4, from 0.6 to 1.3, from 0.6 to 1.1, from 0.7 to 1.4, orfrom 0.7 to 1.2.

Aspect 4. The composition defined in any one of the preceding aspects,wherein the solid activator (or the supported metallocene catalyst) hasa d10 particle size in any range disclosed herein, e.g., greater than orequal to 10 μm, greater than or equal to 11 μm, greater than or equal to12 μm, in a range from 10 to 20 μm, or in a range from 10 to 18 μm.

Aspect 5. The composition defined in any one of the preceding aspects,wherein the solid activator (or the supported metallocene catalyst) hasa d95 particle size in any range disclosed herein, e.g., less than orequal to 65 μm, less than or equal to 60 μm, in a range from 25 to 65μm, or in a range from 28 to 60 μm.

Aspect 6. The composition defined in any one of the preceding aspects,wherein the solid activator (or the supported metallocene catalyst) hasa ratio of d90/d10 in any range disclosed herein, e.g., from 1.5 to 5,from 1.5 to 4, from 1.5 to 3, from 1.8 to 5, from 1.8 to 4, or from 1.8to 3.

Aspect 7. The composition defined in any one of the preceding aspects,wherein the amount of the solid activator (or the supported metallocenecatalyst) having a particle size of less than 10 μm is in any rangedisclosed herein, e.g., less than or equal to 15 wt. %, less than orequal to 10 wt. %, less than or equal to 8 wt. %, less than or equal to5 wt. %, or less than or equal to 2 wt. %.

Aspect 8. The composition defined in any one of the preceding aspects,wherein the amount of the solid activator (or the supported metallocenecatalyst) having a particle size of greater than 45 μm is in any rangedisclosed herein, e.g., less than or equal to 20 wt. %, less than orequal to 15 wt. %, less than or equal to 10 wt. %, less than or equal to5 wt. %, or less than or equal to 2 wt. %.

Aspect 9. The composition defined in any one of the preceding aspects,wherein the amount of the solid activator (or the supported metallocenecatalyst) having a particle size of less than 50 μm is in any rangedisclosed herein, e.g., at least 85 wt. %, at least 88 wt. %, at least90 wt. %, or at least 95 wt. %.

Aspect 10. The composition defined in any one of aspects 1-9, whereinthe solid activator comprises fluorided alumina, chlorided alumina,bromided alumina, sulfated alumina, fluorided silica-alumina, chloridedsilica-alumina, bromided silica-alumina, sulfated silica-alumina,fluorided silica-zirconia, chlorided silica-zirconia, bromidedsilica-zirconia, sulfated silica-zirconia, fluorided silica-titania,fluorided silica-coated alumina, fluorided-chlorided silica-coatedalumina, sulfated silica-coated alumina, phosphated silica-coatedalumina, or any combination thereof.

Aspect 11. The composition defined in any one of aspects 1-9, whereinthe activator comprises fluorided alumina, sulfated alumina, fluoridedsilica-alumina, sulfated silica-alumina, fluorided silica-coatedalumina, fluorided-chlorided silica-coated alumina, sulfatedsilica-coated alumina, or any combination thereof.

Aspect 12. The composition defined in any one of aspects 1-9, whereinthe solid activator comprises a fluorided solid oxide and/or a sulfatedsolid oxide.

Aspect 13. The composition defined in any one of aspects 1-12, whereinthe catalyst composition comprises a co-catalyst, e.g., any suitableco-catalyst.

Aspect 14. The composition defined in any one of aspects 1-13, whereinthe co-catalyst comprises any organoaluminum compound disclosed herein.

Aspect 15. The composition defined in aspect 14, wherein theorganoaluminum compound comprises trimethylaluminum, triethylaluminum,triisobutylaluminum, or a combination thereof.

Aspect 16. The composition defined in any one of the preceding aspects,wherein the catalyst composition is substantially free of aluminoxanecompounds, organoboron or organoborate compounds, ionizing ioniccompounds, or combinations thereof.

Aspect 17. The composition defined in any one of the preceding aspects,wherein the catalyst composition comprises a single metallocenecompound, e.g., a bridged metallocene compound or an unbridgedmetallocene compound.

Aspect 18. The composition defined in any one of aspects 1-16, whereinthe composition comprises metallocene component I comprising anyunbridged metallocene compound disclosed herein and metallocenecomponent II comprising any bridged metallocene compound disclosedherein.

Aspect 19. The composition defined in aspect 18, wherein metallocenecomponent II comprises a bridged zirconium or hafnium based metallocenecompound.

Aspect 20. The composition defined in aspect 18, wherein metallocenecomponent II comprises a bridged zirconium or hafnium based metallocenecompound with an alkenyl substituent.

Aspect 21. The composition defined in aspect 18, wherein metallocenecomponent II comprises a bridged zirconium or hafnium based metallocenecompound with an alkenyl substituent and a fluorenyl group.

Aspect 22. The composition defined in aspect 18, wherein metallocenecomponent II comprises a bridged zirconium or hafnium based metallocenecompound with a cyclopentadienyl group and a fluorenyl group, and withan alkenyl substituent on the bridging group and/or on thecyclopentadienyl group.

Aspect 23. The composition defined in any one of aspects 18-22, whereinmetallocene component II comprises a bridged metallocene compound havingan aryl group substituent on the bridging group.

Aspect 24. The composition defined in any one of aspects 18-23, whereinmetallocene component I comprises an unbridged zirconium or hafniumbased metallocene compound containing two cyclopentadienyl groups, twoindenyl groups, or a cyclopentadienyl and an indenyl group.

Aspect 25. The composition defined in any one of aspects 18-23, whereinmetallocene component I comprises an unbridged zirconium or hafniumbased metallocene compound containing two cyclopentadienyl groups.

Aspect 26. The composition defined in any one of aspects 18-23, whereinmetallocene component I comprises an unbridged Zirconium or hafniumbased metallocene compound containing two indenyl groups.

Aspect 27. The composition defined in any one of aspects 18-23, whereinmetallocene component I comprises an unbridged zirconium or hafniumbased metallocene compound containing a cyclopentadienyl and an indenylgroup.

Aspect 28. The composition defined in any one of aspects 18-23, whereinmetallocene component I comprises an unbridged zirconium basedmetallocene compound containing an alkyl-substituted cyclopentadienylgroup and an alkenyl-substituted indenyl group.

Aspect 29. The composition defined in any one of aspects 18-28, whereina weight ratio of metallocene component I to metallocene component II inthe catalyst composition is in any range disclosed herein, e.g., from10:1 to 1:10, from 5:1 to 1:5, or from 2:1 to 1:2.

Aspect 30. The composition defined in any one of aspects 18-29, whereinthe catalyst composition is produced by a process comprising contacting,in any order, metallocene component I, metallocene component II, thesolid activator, and the co-catalyst.

Aspect 31. The composition defined in any one of the preceding aspects,wherein a catalyst activity of the catalyst composition is in any rangedisclosed herein, e.g., from 150 to 10,000, from 500 to 7,500, or from1,000 to 5,000 grams, of ethylene polymer per gram of solid activatorper hour, under slurry polymerization conditions, with atriisobutylaluminum co-catalyst, using isobutane as a diluent, and witha polymerization temperature of 90° C. and a reactor pressure of 390psig.

Aspect 32. A (slurry) polymerization process comprising: contacting thecatalyst composition defined in any one of aspects 1-31 with an olefinmonomer and an optional olefin comonomer in a polymerization reactorsystem comprising a loop slurry reactor under polymerization conditionsto produce an olefin polymer.

Aspect 33. The process defined in aspect 32, wherein the olefin monomercomprises any olefin monomer disclosed herein, e.g., any C₂-C₂₀ olefin.

Aspect 34. The process defined in aspect 32, wherein the olefin monomerand the optional olefin comonomer independently comprise a C₂-C₂₀alpha-olefin.

Aspect 35. The process defined in any one of aspects 32-34, wherein theolefin monomer comprises ethylene.

Aspect 36. The process defined in any one of aspects 32-35, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising a C₃-C₁₀ alpha-olefin.

Aspect 37. The process defined in any one of aspects 32-36, wherein thecatalyst composition is contacted with ethylene and an olefin comonomercomprising 1-butene, 1-hexene, 1-octene, or a mixture thereof.

Aspect 38. The process defined in any one of aspects 32-37, wherein thepolymerization reactor system comprises only one loop slurry reactor.

Aspect 39. The process defined in any one of aspects 32-37, wherein thepolymerization reactor system comprises two or more reactors, at leastone of which is the loop slurry reactor.

Aspect 40. The process defined in any one of aspects 32-39, wherein theolefin polymer comprises any olefin polymer disclosed herein.

Aspect 41. The process defined in any one of aspects 32-40, wherein theolefin polymer comprises an ethylene homopolymer, an ethylene/1-butenecopolymer, an ethylene/1-hexene copolymer, and/or an ethylene/I-octenecopolymer.

Aspect 42. The process defined in any one of aspects 32-41, wherein theolefin polymer comprises an ethylene/l-hexene copolymer.

Aspect 43. The process defined in any one of aspects 32-42, wherein thepolymerization conditions comprise a polymerization reaction temperaturein a range from 60° C. to 120° C. and a reaction pressure in a rangefrom 200 to 1000 psig (1.4 to 6.9 MPa).

Aspect 44. The process defined in any one of aspects 32-43, wherein thepolymerization conditions are substantially constant, e.g., for aparticular polymer grade.

Aspect 45. The process defined in any one of aspects 3244, wherein nohydrogen is added to the polymerization reactor system.

Aspect 46. The process defined in any one of aspects 32-44, whereinhydrogen is added to the polymerization reactor system.

Aspect 47. The process defined in any one of aspects 32-46, wherein theolefin polymer has a density in any range disclosed herein, e.g., from0.90 to 0.97, from 0.92 to 0.96, from 0.93 to 0.955, or from 0.94 to0.955 g/cm³.

Aspect 48. The process defined in any one of aspects 3247, wherein theolefin polymer has a Mw in any range disclosed herein, e.g., from 100 to50) kg/mol, from 150 to 350 kg/mol, or from 200 to 320 kg/mol.

Aspect 49. The process defined in any one of aspects 32-48, wherein theolefin polymer has a ratio of Mw/Mn in any range disclosed herein, e.g.,from 5 to 40, from 7 to 25, or from 8 to 15.

Aspect 50. The process defined in any one of aspects 32-49, wherein theolefin polymer has a HLMI in any range disclosed herein, e.g., from 1 to80, from 2 to 40, from 2 to 30, or from 1 to 20 g/10 min.

Aspect 51. The process defined in any one of aspects 32-50, wherein theolefin polymer contains, independently, less than 0.1 ppm (by weight),less than 0.08 ppm, less than 0.05 ppm, or less than 0.03 ppm, of Mg, V.Ti, or Cr.

Aspect 52. The process defined in any one of aspects 32-51, wherein theolefin polymer is characterized by a film gel count in any rangedisclosed herein, e.g., less than 100, less than 50, less than 25, lessthan 10, or less than 5 gels per ft² of 25 micron film (gels encompassany film defect with a size greater than 200 microns).

Aspect 53. An olefin polymer produced by the process defined in any oneof aspects 32-52.

Aspect 54. An ethylene polymer (e.g., in the form of pellets) having (orcharacterized by): a high load melt index (HLMI) in a range from 4 to 10g/10 min a density in a range from 0.944 to 0.955 g/cm³; and a highermolecular weight component and a lower molecular weight component,wherein: the higher molecular weight component has a Mn in a range from280,000 to 440,000 g/mol; and the lower molecular weight component has aMw in a range from 30,000 to 45,000 g/mol, and a ratio of Mz/Mw in arange from 2.3 to 3.4.

Aspect 55. The polymer defined in aspect 54, wherein the ethylenepolymer has a HLMI in any range disclosed herein, e.g., from 4 to 9,from 4 to 8, from 5 to 10, from 5 to 9, or from 5 to 8 g/10 min.

Aspect 56. The polymer defined in aspect 54 or 55, wherein the ethylenepolymer has a density in any range disclosed herein, e.g., from 0.944 to0.952, from 0.945 to 0.955, from 0.945 to 0.953, from 0.945 to 0.95,from 0.946 to 0.955, or from 0.946 to 0.952 g/cm³.

Aspect 57. The polymer defined in any one of aspects 54-56, wherein thelower molecular weight component has a Mw in any range disclosed herein,e.g., from 30,000 to 43,000, from 30,000 to 41,000, from 31,000 to45,000, from 31,000 to 42,000, from 31,000 to 40,000, from 32,000 to44.000, or from 32,000 to 42,000 g/mol.

Aspect 58. The polymer defined in any one of aspects 54-57, wherein thehigher molecular weight component has a Mn in any range disclosedherein, e.g., from 280,000 to 425,000, from 280,000 to 400,000, from290,000 to 410,000, from 300,000 to 440,000, or from 300,000 to 400,000g/mol.

Aspect 59. The polymer defined in any one of aspects 54-58, wherein thelower molecular weight component has a ratio of Mz/Mw in any rangedisclosed herein, e.g., from 2.3 to 3.2, from 2.35 to 3.0, from 2.4 to3.3, from 2.4 to 3.2, or from 2.4 to 3.1.

Aspect 60. The polymer defined in any one of aspects 54-59, wherein anamount of the lower molecular weight component, based on the totalpolymer, is in any range of weight percentages disclosed herein, e.g.,from 56 to 72 wt. %, from 56 to 70 wt. %, from 58 to 72 wt. %, from 58to 70 wt. %, or from 60 to 68 wt. % Aspect 61. The polymer defined inany one of aspects 54-60, wherein the lower molecular weight componenthas a Mn in any range disclosed herein, e.g., from 4,000 to 10,000, from4,000 to 9,000, from 5.000 to 10,000, from 5.000 to 9,000, or from 5,500to 8,500 g/mol.

Aspect 62. The polymer defined in any one of aspects 54-61, wherein thelower molecular weight component has a Mz in any range disclosed herein,e.g., from 70,000 to 130,000, from 70,000 to 115,000, from 75,000 to130,000, from 75,000 to 120,000, or from 75,000 to 115,000 g/mol.

Aspect 63. The polymer defined in any one of aspects 54-62, wherein thehigher molecular weight component has a ratio of Mw/Mn in any rangedisclosed herein, e.g., from 1.6 to 2.4, from 1.7 to 2.4, from 1.7 to2.3, from 1.8 to 2.4, from 1.8 to 2.3, from 1.9 to 2.4, or from 1.9 to2.3.

Aspect 64. The polymer defined in any one of aspects 54-63, wherein thehigher molecular weight component has a Mz in any range disclosedherein, e.g., from 900,000 to 1,600,000, from 1,000,000 to 1,500,000,from 1,000,000 to 1,400,000, from 1,100,000 to 1,600,000, or from1,100,000 to 1,500,000 g/mol.

Aspect 65. The polymer defined in any one of aspects 54-64, wherein theethylene polymer has a Mw in any range disclosed herein, e.g., from230,000 to 330,000, from 230,000 to 320,000, from 240,000 to 330,000, orfrom 240,000 to 320,000 g/mol.

Aspect 66. The polymer defined in any one of aspects 54-65, wherein theethylene polymer has a ratio of Mw/Mn in any range disclosed herein,e.g., from 20 to 45, from 20 to 42, from 22 to 44, from 25 to 45, orfrom 25 to 42.

Aspect 67. The polymer defined in any one of aspects 54-66, wherein theethylene polymer has a CY-a parameter in any range disclosed herein,e.g., from 0.45 to 0.65, from 0.47 to 0.63, from 0.47 to 0.61, from 0.5to 0.65, from 0.5 to 0.63, or from 0.5 to 0.6.

Aspect 68. The polymer defined in any one of aspects 54-67, wherein theethylene polymer has a relaxation time (Tau(eta) or T(q)) in any rangedisclosed herein, e.g., from 1.5 to 4, from 1.5 to 3.7, from 2 to 4, orfrom 2 to 3.6 sec.

Aspect 69. The polymer defined in any one of aspects 54-68, wherein theethylene polymer has a viscosity at 100 sec⁻¹ (eta @r 100 or @ 100) inany range disclosed herein, e.g., from 2000 to 3600, from 2000 to 3500,from 2100 to 3600, or from 2100 to 3500 Pa-sec.

Aspect 70. The polymer defined in any one of aspects 54-69, wherein theethylene polymer has a ratio of viscosity at 0.1 sec⁻¹ to viscosity at100 sec⁻¹ (q @ 0.1/η @ 100) in any range disclosed herein, e.g., from 38to 72, from 40 to 68, from 46 to 68, or from 52 to 72.

Aspect 71. The polymer defined in any one of aspects 54-70, wherein theethylene polymer contains, independently, less than 0.1 ppm (by weight),less than 0.08 ppm, less than 0.05 ppm, or less than 0.03 ppm, of Mg, V,Ti, or Cr.

Aspect 72. The polymer defined in any one of aspects 54-71, wherein theethylene polymer is characterized by a film gel count in any rangedisclosed herein, e.g., less than 100, less than 50, less than 25, lessthan 10, or less than 5 gels per ft² of 25 micron film (gels encompassany film defect with a size greater than 200 microns).

Aspect 73. The polymer defined in any one of aspects 54-72, wherein theethylene polymer is a single reactor product, e.g., not a post-reactorblend of two polymers, for instance, having different molecular weightcharacteristics.

Aspect 74. The polymer defined in any one of aspects 54-73, wherein theethylene polymer comprises an ethylene/α-olefin copolymer.

Aspect 75. The polymer defined in any one of aspects 54-74, wherein theethylene polymer comprises an ethylene homopolymer, an ethylene/1-butenecopolymer, an ethylene/1-hexene copolymer, and/or an ethylene/1-octenecopolymer.

Aspect 76. The polymer defined in any one of aspects 54-75, wherein theethylene polymer comprises an ethylene/1-hexene copolymer.

Aspect 77. An article comprising the ethylene polymer defined in any oneof aspects 54-76.

Aspect 78. An article comprising the ethylene polymer defined in any oneof aspects 54-76, wherein the article is an agricultural film, anautomobile part, a bottle, a container for chemicals, a drum, a fiber orfabric, a food packaging film or container, a food service article, afuel tank, a geomembrane, a household container, a liner, a moldedproduct, a medical device or material, an outdoor storage product,outdoor play equipment, a pipe, a sheet or tape, a toy, or a trafficbarrier.

Aspect 79. A film comprising (or produced from) the polymer defined inany one of aspects 54-76.

Aspect 80. The film defined in aspect 79, wherein the film has a dartimpact strength in any range disclosed herein, e.g., greater than orequal to 150 g/mil, greater than or equal to 250 g/mil, from 150 to 750g/mil, or from 250 to 600 g/mil.

Aspect 81. The film defined in aspect 79 or 80, wherein the film has agel count in any range disclosed herein, e.g., less than 100, less than50, less than 25, less than 10, or less than 5 gels per ft² of film(gels encompass any film defect with a size greater than 200 microns).

Aspect 82. The film defined in any one of aspects 79-81, wherein thefilm has an average thickness in any range disclosed herein, e.g., from0.4 to 20 mils, from 0.5 to 8 mils, from 0.8 to 5 mils, from 0.7 to 2mils, or from 0.7 to 1.5 mils.

Aspect 83. The film defined in any one of aspects 79-82, wherein thefilm is a blown film.

Aspect 84. The process defined in any one of aspects 32-52, wherein theolefin polymer produced is defined in any one of aspects 54-76.

Aspect 85. An ethylene polymer defined in any one of aspects 54-76produced by the process defined in any one of aspects 32-52.

Aspect 86. An ethylene polymer (fluff or powder) composition having (orcharacterized by): a d50 average particle size in a range from 150 to600 μm; a particle size span ((d90−d10)/d50) in a range from 0.5 to 1.6;less than or equal to 20 wt. % of the composition with a particle sizeof less than 100 μm; and less than or equal to 5 wt. % of thecomposition with a particle size of greater than 1000 μm.

Aspect 87. The composition defined in aspect 86, wherein the d50 averageparticle size is in any range disclosed herein, e.g., from 150 to 450μm, from 150 to 325 μm, from 150 to 300 μm, from 175 to 325 μm, from 175to 275 μm, from 200 to 400 μm, or from 200 to 275 μm.

Aspect 88. The composition defined in aspect 86 or 87, wherein the span((d90−d10)/d50) is an any range disclosed herein, e.g., from 0.75 to1.5, from 1 to 1.6, from 1.1 to 1.6, or from 1.1 to 1.5.

Aspect 89. The composition defined in any one of aspects 86-88, whereinthe amount of the composition having a particle size of greater than1000 μm is in any range disclosed herein, e.g., less than or equal to 3wt. %, less than or equal to 2 wt %, or less than or equal to 1 wt. %.

Aspect 90. The composition defined in any one of aspects 86-89, whereinthe amount of the composition having a particle size of less than 100 μmis in any range disclosed herein, e.g., less than or equal to 10 wt. %,less than or equal to 5 wt. %, from 1 to 10 wt. %, or from 1 to 5 wt. %.

Aspect 91. The composition defined in any one of aspects 86-90, whereinthe composition has a d90 particle size in any range disclosed herein,e.g., from 300 to 800 μm, from 300 to 600 μm, from 350 to 550 μm, from375 to 525 μm, from 400 to 750 μm, or from 400 to 500 μm.

Aspect 92. The composition defined in any one of aspects 86-91, whereinthe composition has a ratio of d90/d10 in any range disclosed herein,e.g., from 2 to 5, from 2 to 4, from 2.2 to 3.8, from 2.4 to 5, from 2.4to 3.6, or from 2.7 to 3.3.

Aspect 93. The composition defined in any one of aspects 86-92, whereinthe composition has a HLMI in any range disclosed herein, e.g., from 4to 10, from 4 to 9, from 4 to 8, from 5 to 10, from 5 to 9, or from 5 to8 g/10 min.

Aspect 94. The composition defined in any one of aspects 86-93, whereinthe composition has a density in any range disclosed herein, e.g., from0.944 to 0.955, from 0.944 to 0.952, from 0.945 to 0.955, from 0.945 to0.953, from 0.945 to 0.95, from 0.946 to 0.955, or from 0.946 to 0.952g/cm³.

We claim:
 1. An ethylene polymer having: a high load melt index (HLMI)in a range from 4 to 10 g/10 min; a density in a range from 0.944 to0.955 g/cm³; and a higher molecular weight component and a lowermolecular weight component, wherein: the higher molecular weightcomponent has a Mn in a range from 280,000 to 440,000 g/mol; and thelower molecular weight component has a Mw in a range from 30,000 to45,000 g/mol and a ratio of Mz/Mw in a range from 2.3 to 3.4.
 2. Anarticle comprising the ethylene polymer of claim
 1. 3. The article ofclaim 2, wherein the ethylene polymer comprises an ethylene/1-butenecopolymer, an ethylene/1-hexene copolymer, and/or an ethylene/1-octenecopolymer.
 4. The ethylene polymer of claim 1, wherein: the HLMI is from5 to 9 g/10 min; the density is from 0.945 to 0.953 g/cm³; the Mn isfrom 290,000 to 410,000 g/mol; the Mw is from 31,000 to 42,000 g/mol;and the ratio of Mz/Mw is from 2.4 to 3.3.
 5. The ethylene polymer ofclaim 1, wherein: an amount of the lower molecular weight component,based on the total polymer, is in a range from 56 to 72 wt %; and theethylene polymer comprises an ethylene/1-butene copolymer, anethylene/1-hexene copolymer, and/or an ethylene/1-octene copolymer. 6.The ethylene polymer of claim 5, wherein the ethylene polymer ischaracterized by a film gel count of less than 50 gels per ft² of 25micron film.
 7. A film comprising the ethylene polymer of claim
 5. 8.The film of claim 7, wherein the film has: a dart impact from 150 to 750g/mil; and a gel count of less than 50 gels per ft² of film.
 9. Theethylene polymer of claim 1, wherein the ethylene polymer has: a CY-aparameter from 0.45 to 0.65; a relaxation time from 1.5 to 4 sec; aviscosity at 100 sec⁻¹ from 2000 to 3600 Pa-sec; and a ratio ofviscosity at 0.1 sec⁻¹ to viscosity at 100 sec⁻¹ from 38 to
 72. 10. Theethylene polymer of claim 1, wherein the ethylene polymer comprises anethylene/1-butene copolymer, an ethylene/1-hexene copolymer, and/or anethylene/1-octene copolymer.
 11. The ethylene polymer of claim 10,wherein the ethylene polymer contains less than 0.1 ppm by weight,independently, of Mg, V, Ti, and Cr.
 12. The ethylene polymer of claim10, wherein: a Mw of the ethylene polymer is in a range from 230,000 to330,000 g/mol; and a ratio of Mw/Mn of the ethylene polymer is in arange from 20 to
 45. 13. An article comprising the ethylene polymer ofclaim
 12. 14. A film comprising the ethylene polymer of claim 12,wherein the film has: a dart impact from 150 to 750 g/mil; and a gelcount of less than 50 gels per ft² of film.
 15. The ethylene polymer ofclaim 12, wherein a Mz of the lower molecular weight component is in arange from 75,000 to 120,000 g/mol.
 16. The ethylene polymer of claim 4,wherein the ethylene polymer comprises an ethylene/α-olefin copolymer.17. The ethylene polymer of claim 16, wherein the ethylene polymer ischaracterized by a film gel count of less than 50 gels per ft² of 25micron film.
 18. The ethylene polymer of claim 4, wherein an amount ofthe lower molecular weight component, based on the total polymer, is ina range from 56 to 72 wt %.
 19. The ethylene polymer of claim 4, whereinthe ethylene polymer has: a CY-a parameter from 0.45 to 0.65; arelaxation time from 1.5 to 4 sec; a viscosity at 100 sec⁻¹ from 2000 to3600 Pa-sec; and a ratio of viscosity at 0.1 sec⁻¹ to viscosity at 100sec⁻¹ from 38 to
 72. 20. An article comprising the ethylene polymer ofclaim
 19. 21. The ethylene polymer of claim 19, wherein the ethylenepolymer comprises an ethylene/1-butene copolymer, an ethylene/1-hexenecopolymer, and/or an ethylene/1-octene copolymer.
 22. The ethylenepolymer of claim 21, wherein a Mz of the lower molecular weightcomponent is in a range from 75,000 to 120,000 g/mol.